c54099_nq.htm -- Converted by SEC Publisher, created by BCL Technologies Inc., for SEC Filing

UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

FORM N-Q

QUARTERLY SCHEDULE OF PORTFOLIO HOLDINGS OF REGISTERED
MANAGEMENT INVESTMENT COMPANY

Investment Company Act file number 811-21178

Name of Fund: BlackRock Insured Municipal Income Trust (BYM)

Fund Address: 100 Bellevue Parkway, Wilmington, DE 19809

Name and address of agent for service: Donald C. Burke, Chief Executive Officer, BlackRock Insured Municipal Income Trust, 800 Scudders Mill Road, Plainsboro, NJ, 08536. Mailing address: P.O. Box 9011, Princeton, NJ, 08543-9011

Registrant’s telephone number, including area code: (800) 882-0052, Option 4

Date of fiscal year end: 08/31/2008

Date of reporting period: 03/01/2008 – 05/31/2008

Item 1 – Schedule of Investments

BlackRock Insured Municipal Income Trust          
Schedule of Investments May 31, 2008 (Unaudited) (Percentages shown are based on Net Assets)
      Par      
State Municipal Bonds   (000)    
Value
Alabama - 0.6% Jefferson County, Alabama, Limited Obligation School Warrants,        
  Series A, 4.75%, 1/01/25 $            2,800            
$
           2,408,924
Arizona - 2.3% Phoenix, Arizona, Civic Improvement Corporation, Excise Tax        
  Revenue Bonds (Civic Plaza Expansion Project),          
  Sub-Series A, 5%, 7/01/41 (a)   5,000     5,023,450
  Salt Verde Financial Corporation, Arizona, Senior Gas Revenue        
  Bonds, 5%, 12/01/37   4,000     3,540,160
            8,563,610
California - 30.9%                   Arcadia, California, Unified School District, Capital Appreciation, GO        
  (Election of 2006), Series A, 4.96%, 8/01/39 (b)(c)   2,000     352,960
  California Infrastructure and Economic Development Bank, First Lien        
  Revenue Bonds (Bay Area Toll Bridges Retrofit), Series A, 5%,        
  1/01/28 (d)(e)   10,100     10,945,168
  California State Department of Water Resources, Power Supply        
  Revenue Bonds, Series A, 5.375%, 5/01/12 (e)   14,000     15,417,780
  Coast Community College District, California, GO, Refunding        
  (Election of 2002), Series C, 5.504%, 8/01/13 (b)(c)   7,450     5,713,554
  Coast Community College District, California, GO, Refunding        
  (Election of 2002), Series C, 5.39%, 8/01/36 (b)(c)   4,200     910,896
  Fresno, California, Unified School District, GO          
  (Election of 2001), Series E, 5%, 8/01/30 (b)   1,100     1,136,421
  Golden State Tobacco Securitization Corporation of California,        
  Tobacco Settlement Revenue Bonds, Series A-1,          
  6.625%, 6/01/13 (e)   6,500     7,424,170
  Golden State Tobacco Securitization Corporation of California,        
  Tobacco Settlement Revenue Bonds, Series A-1,          
  6.75%, 6/01/13 (e)   14,500     16,644,115
  Los Angeles, California, Municipal Improvement Corporation, Lease        
  Revenue Bonds, Series B1, 4.75%, 8/01/37 (a)   4,000     3,913,200
  Metropolitan Water District of Southern California, Waterworks        
  Revenue Bonds, Series B-1, 5%, 10/01/33 (a)   17,500     17,801,875
  Monterey Peninsula Community College District, California, GO,        
  CABS, Series C, 5.15%, 8/01/31 (b)(c)   13,575     3,724,980
  Monterey Peninsula Community College District, California, GO,        
  CABS, Series C, 5.16%, 8/01/32 (b)(c)   14,150     3,683,245
  Orange County, California, Sanitation District, COP,          
  Series B, 5%, 2/01/31 (b)   2,500     2,552,750
  Rancho Cucamonga, California, Redevelopment Agency, Tax        
  Allocation Refunding Bonds (Rancho Redevelopment Project), Series        
  A, 5%, 9/01/34 (f)   500     501,800
Portfolio Abbreviations          
To simplify the listings of BlackRock Insured Municipal Income Trust's portfolio holdings in the Schedule of      
Investments, we have abbreviated the names of many of the securities according to the list below.        

            AMT       Alternative Minimum Tax (subject to)                         GO       General Obligation Bonds
  CABS   Capital Appreciation Bonds   IDA   Industrial Development Authority
  COP   Certificates of Participation   PCR   Pollution Control Revenue Bonds
  EDA   Economic Development Authority        

1

BlackRock Insured Municipal Income Trust            
Schedule of Investments May 31, 2008 (Unaudited)   (Percentages shown are based on Net Assets)
        Par      
State Municipal Bonds     (000)              
Value
  Sacramento, California, Unified School District, GO (Election of        
  2002), 5%, 7/01/30 (f)   $            2,700  
$
            2,771,145
  San Joaquin Hills, California, Transportation Corridor Agency, Toll        
  Road Revenue Refunding Bonds, Series A, 5.45%, 1/15/31 (c)(f) 53,000     13,759,860
  University of California Revenue Bonds, Series O, 5%,            
  9/01/10 (a)(e)     9,000     9,615,690
              116,869,609
District of Columbia - District of Columbia Tobacco Settlement Financing Corporation,        
2.5% Asset-Backed Revenue Refunding Bonds, 6.75%, 5/15/40 9,500     9,551,775
Florida - 9.4% Florida State Department of Environmental Protection, Preservation        
  Revenue Bonds, Series B, 5%, 7/01/27 (f)     7,500     7,648,575
  Highlands County, Florida, Health Facilities Authority, Hospital        
  Revenue Bonds (Adventist Health System),            
  Series C, 5.25%, 11/15/36     1,650     1,621,240
  Miami-Dade County, Florida, Aviation Revenue Bonds (Miami        
  International Airport), Series B, 5%, 10/01/37 (a)     9,500     9,313,040
  Miami-Dade County, Florida, School Board, COP, Refunding,        
  Series B, 5.25%, 5/01/31 (g)     3,700     3,771,484
  Miami-Dade County, Florida, School Board, COP, Refunding,        
  Series B, 5%, 5/01/33 (g)     7,500     7,505,475
  Miami-Dade County, Florida, Special Obligation Revenue Bonds, Sub-        
  Series A, 5.25%, 10/01/38 (c)(f)     25,520     4,530,821
  Miami, Florida, Special Obligation Revenue Bonds (Street and        
  Sidewalk Improvement Program), 5%, 1/01/37 (f)     1,000     1,004,490
              35,395,125
Georgia - 3.1% Atlanta, Georgia, Water and Wastewater Revenue Bonds, 5%,        
  11/01/34 (b)     7,000     7,118,790
  Atlanta, Georgia, Water and Wastewater Revenue Bonds, 5%,        
  11/01/37 (b)     4,475     4,543,512
              11,662,302
Illinois - 6.7% Bolingbrook, Illinois, GO, Refunding, Series A, 4.75%,            
  1/01/38 (f)     2,500     2,430,225
  Chicago, Illinois, Special Transportation Revenue Bonds, 5.25%,        
  1/01/27 (d)(e)     11,550     12,086,498
  Illinois Municipal Electric Agency, Power Supply Revenue Bonds,        
  Series A, 5.25%, 2/01/27 (a)(f)     5,000     5,182,800
  Metropolitan Pier and Exposition Authority, Illinois, Dedicated State        
  Tax Revenue Refunding Bonds (McCormick Place Expansion), 5.50%,        
  6/15/28 (c)(f)     15,000     5,435,100
              25,134,623
Louisiana - 1.5% Louisiana State, Gas and Fuels Tax Revenue Bonds, Series A, 5%,        
  5/01/35 (a)     5,450     5,510,113
Massachusetts - 3.6%            Massachusetts Bay Transportation Authority, Sales Tax Revenue        
  Refunding Bonds, Senior Series A-2, 5.12%, 7/01/35 (c)     3,200     746,016
  Massachusetts State Turnpike Authority, Metropolitan Highway        
  System Revenue Refunding Bonds, Sub-Series A, 5%, 1/01/39 (d) 13,000     12,938,900
              13,684,916

2

BlackRock Insured Municipal Income Trust            
Schedule of Investments May 31, 2008 (Unaudited)   (Percentages shown are based on Net Assets)
        Par      
State Municipal Bonds     (000)    
Value
Michigan - 4.5%                      Detroit, Michigan, Sewage Disposal System, Second Lien Revenue        
  Bonds, Series B, 5%, 7/01/33 (a)(f)   $            4,000            
$
            4,010,360
  Detroit, Michigan, Sewage Disposal System, Second Lien Revenue        
  Bonds, Series B, 5%, 7/01/36 (a)(f)     7,000     7,008,890
  Detroit, Michigan, Water Supply System Revenue Bonds, Senior Lien,        
  Series A, 5%, 7/01/30 (a)     1,000     980,300
  Detroit, Michigan, Water Supply System Revenue Bonds, Senior Lien,        
  Series A, 5%, 7/01/34 (f)     3,000     3,002,520
  Michigan State Hospital Finance Authority, Revenue Refunding Bonds        
  (Henry Ford Health System), Series A, 5%, 11/15/38     2,000     1,886,720
              16,888,790
Nevada - 7.5% Reno, Nevada, Sales and Room Tax Revenue Refunding Bonds        
  (ReTrac-Reno Transportation Rail Access Corridor Project), Senior        
  Lien, 5.125%, 6/01/12 (d)(e)     5,000     5,397,350
  Truckee Meadows, Nevada, Water Authority, Water Revenue Bonds,        
  Series A, 5%, 7/01/11 (b)(e)     10,000     10,655,000
  Truckee Meadows, Nevada, Water Authority, Water Revenue Bonds,        
  Series A, 5.125%, 7/01/11 (b)(e)     6,500     6,949,605
  Truckee Meadows, Nevada, Water Authority, Water Revenue Bonds,        
  Series A, 5.25%, 7/01/11 (b)(e)     5,000     5,364,250
              28,366,205
New York - 1.8% Metropolitan Transportation Authority, New York, Revenue Bonds,        
  Series A, 5%, 11/15/31 (b)     6,450     6,647,176
Pennsylvania - 2.1% Lebanon County, Pennsylvania, Health Facilities Authority, Hospital        
  Revenue Bonds (Good Samaritan Hospital Project),            
  6%, 11/15/35     2,500     2,504,525
  Philadelphia, Pennsylvania, Gas Works Revenue Bonds, 3rd Series,        
  5.125%, 8/01/11 (b)(e)     5,200     5,577,104
              8,081,629
South Carolina - 5.0% South Carolina Transportation Infrastructure Bank Revenue Bonds,        
  Junior Lien, Series B, 5.125% due 10/01/2011 (d)(e)     10,000     10,748,400
  South Carolina Transportation Infrastructure Bank Revenue Bonds,        
  Series A, 5%, 10/01/33 (d)     8,000     8,049,040
              18,797,440
Tennessee - 5.2% Knox County, Tennessee, Health, Educational and Housing Facilities        
  Board, Hospital Facilities Revenue Refunding Bonds (Covenant        
  Health), Series A, 5.84%, 1/01/22 (b)(c)     11,705     5,556,715
  Knox County, Tennessee, Health, Educational and Housing Facilities        
  Board, Hospital Facilities Revenue Refunding Bonds (Covenant        
  Health), Series A, 5.88%, 1/01/23 (b)(c)     9,260     4,121,070
  Knox County, Tennessee, Health, Educational and Housing Facilities        
  Board, Hospital Facilities Revenue Refunding Bonds (Covenant        
  Health), Series A, 5.90%, 1/01/24 (b)(c)     8,500     3,554,275
  Knox County, Tennessee, Health, Educational and Housing Facilities        
  Board, Hospital Facilities Revenue Refunding Bonds (Covenant        
  Health), Series A, 5.91%, 1/01/25 (b)(c)     6,850     2,694,584

3

BlackRock Insured Municipal Income Trust          
Schedule of Investments May 31, 2008 (Unaudited) (Percentages shown are based on Net Assets)
      Par      
State Municipal Bonds   (000)    
Value
  Knox County, Tennessee, Health, Educational and Housing Facilities        
  Board, Hospital Facilities Revenue Refunding Bonds (Covenant        
  Health), Series A, 5.93%, 1/01/26 (b)(c) $            5,000            
$
            1,842,600
  Knox County, Tennessee, Health, Educational and Housing Facilities        
  Board, Hospital Facilities Revenue Refunding Bonds (Covenant        
  Health), Series A, 5.07%, 1/01/41 (c)   10,000     1,291,800
  Tennessee Energy Acquisition Corporation, Gas Revenue Bonds,        
  Series A, 5.25%, 9/01/26   650     636,500
            19,697,544
Texas - 28.8%                         Coppell, Texas, Independent School District, GO, Refunding, 5.64%,        
  8/15/30 (c)   10,030     3,186,832
  Dallas, Texas, Area Rapid Transit Revenue Refunding Bonds, Senior        
  Lien, 5%, 12/01/11 (d)(e)   2,350     2,519,411
  Harris County-Houston Sports Authority, Texas, Revenue Refunding        
  Bonds, Junior Lien, Series H, 5.811%, 11/15/38 (c)(f)   5,785     921,377
  Harris County-Houston Sports Authority, Texas, Revenue Refunding        
  Bonds, Junior Lien, Series H, 5.826%, 11/15/39 (c)(f)   6,160     913,282
  Harris County-Houston Sports Authority, Texas, Revenue Refunding        
  Bonds, Third Lien, Series A-3, 5.98%, 11/15/38 (c)(f)   26,890     4,335,744
  Harris County-Houston Sports Authority, Texas, Revenue Refunding        
  Bonds, Third Lien, Series A-3, 5.99%, 11/15/39 (c)(f)   27,675     4,153,187
  Harris County, Texas, GO, Refunding, 5.49%, 8/15/25 (c)(f) 7,485     3,183,670
  Harris County, Texas, GO, Refunding, 5.20%, 8/15/28 (c)(f) 10,915     3,898,620
  Harris County, Texas, Toll Road Revenue Refunding Bonds, Senior        
  Lien, 5%, 8/15/30 (b)   5,510     5,593,091
  Lewisville, Texas, Independent School District, Capital Appreciation        
  and School Building, GO, Refunding, 4.67%,          
  8/15/24 (a)(c)   5,315     2,222,255
  North Texas Tollway Authority, System Revenue Refunding Bonds,        
  5.75%, 1/01/40 (f)   23,050     24,406,723
  North Texas Tollway Authority, System Revenue Refunding Bonds,        
  First Tier, Series A, 6%, 1/01/25   750     806,527
  San Antonio, Texas, Water System Revenue Refunding Bonds,        
  5.125%, 5/15/29 (a)   9,350     9,435,740
  San Antonio, Texas, Water System Revenue Refunding Bonds,        
  5.125%, 5/15/34 (a)   10,000     10,066,000
  Texas State Turnpike Authority, Central Texas Turnpike System        
  Revenue Bonds, First Tier, Series A, 5%, 8/15/42 (d)   30,145     29,719,654
  Tyler, Texas, Health Facilities Development Corporation, Hospital        
  Revenue Bonds (Mother Frances Hospital Regional Health Care        
  Center), 6%, 7/01/12 (e)   3,000     3,335,040
            108,697,153
Virginia - 2.0% Chesterfield County, Virginia, IDA, PCR (Virginia Electric and Power        
  Company), Series A, 5.875%, 6/01/17   3,000     3,176,640

4

BlackRock Insured Municipal Income Trust          
Schedule of Investments May 31, 2008 (Unaudited) (Percentages shown are based on Net Assets)
      Par      
State Municipal Bonds   (000)    
Value
  Chesterfield County, Virginia, IDA, PCR, Refunding (Virginia Electric        
  and Power Company), Series B, 5.875%, 6/01/17 $             4,000             $            4,249,000
            7,425,640
Washington - 8.3%                Central Washington University, System Revenue Bonds, 5%, 5/01/34        
  (a)   9,610     9,499,485
  Chelan County, Washington, Public Utility District Number 001,        
  Consolidated Revenue Bonds (Chelan Hydro System), AMT, Series C,        
  5.125%, 7/01/33 (d)   3,655     3,715,125
  Port of Seattle, Washington, Revenue Bonds, Series A,          
  5%, 4/01/31 (a)   4,500     4,546,485
  Washington State, GO, Series 02-A, 5%, 7/01/25 (b)   6,380     6,595,261
  Washington State Health Care Facilities Authority Revenue Bonds        
  (MultiCare Health System), Series C, 5.50%, 8/15/43 (g)   7,000     7,211,120
            31,567,476
West Virginia - 0.3% West Virginia EDA, Lease Revenue Bonds (Correctional, Juvenile and        
  Public Safety Facilities), Series A, 5%, 6/01/29 (f)   1,295     1,311,058
Puerto Rico - 0.3% Puerto Rico Commonwealth Aqueduct and Sewer Authority, Senior        
  Lien Revenue Bonds, Series A, 6%, 7/01/44 (h)   1,080     1,154,963
  Total Municipal Bonds          
  (Cost - $465,740,991) - 126.4%         477,416,071
  Municipal Bonds Transferred to          
  Tender Option Bond Trusts (i)          
California - 8.0% San Diego County, California, Water Authority Revenue          
  Refunding Bonds, COP, Series 2008 A, 5%, 5/01/33 (b)   4,875     5,020,909
  San Francisco, California, City and County Public Utilities          
  Commission, Water Revenue Refunding Bonds, Series A,          
  5%, 11/01/31 (b)   15,000     15,215,700
  University of California Revenue Bonds (Multi-Purpose Projects),        
  Series C, 4.75%, 5/15/37   10,000     9,860,400
            30,097,009
Florida - 1.3% Duval County, Florida, School Board COP, 5%, 7/01/33 (b)   2,800     2,804,034
  Jacksonville, Florida, Health Facilities Authority, Hospital Revenue        
  Bonds (Baptist Medical Center Project), 5%, 8/15/37 (b)   1,995     2,006,551
            4,810,585
Illinois - 6.5% Metropolitan Pier & Exposition Authority, Illinois, Dedicated State        
  Tax Revenue Refunding Bonds (McCormick Place Expansion          
  Project), Series A, 5%, 12/15/28 (f)   24,010     24,534,028
Louisiana - 2.6% Louisiana State, Gas and Fuels Tax Revenue Bonds,          
  Series A, 4.75%, 5/01/39 (b)   9,950     9,854,082
Massachusetts - 3.5% Massachusetts State School Building Authority, Dedicated          
  Sales Tax Revenue Bonds, Series A, 5%, 8/15/30 (b)   13,000     13,347,230
Michigan - 0.9% Detroit, Michigan, Sewage Disposal System Revenue Bonds          
  (Second Lien), Series E, 5.75%, 7/01/31 (a)   3,000     3,324,330
New York - 3.2% Erie County, New York, IDA, School Facility Revenue Bonds          
  (City of Buffalo Project), Series A, 5.75%, 5/01/28 (b)   4,500     4,954,455
  Metropolitan Transportation Authority, New York, Revenue Bonds,        
  Series A, 5%, 11/15/31 (f)   7,000     7,204,120
            12,158,575

5

BlackRock Insured Municipal Income Trust          
Schedule of Investments May 31, 2008 (Unaudited) (Percentages shown are based on Net Assets)
  Total Municipal Bonds Transferred to   Par      
State Tender Option Bond Trusts (i)   (000)            Value
Texas - 2.6% Northside Texas, Independent School District, GO,          
  5.125%, 6/15/29
$
           9,500            
$
            9,776,925
Utah - 1.4% Utah Transit Authority, Sales Tax Revenue Bonds,          
  Series A, 5%, 6/15/36 (b)   5,000     5,165,560
Washington - 1.4%               Central Puget Sound Regional Transportation Authority,          
  Washington, Sales and Use Tax Revenue Bonds, Series A,          
  5%, 11/01/32 (b)   3,500     3,603,215
  King County, Washington, Sewer Revenue Refunding Bonds, 5%,        
  1/01/36 (b)   2,200     2,252,363
            5,855,578
  Total Municipal Bonds Transferred to Tender Option Bond Trusts        
  (Cost - $117,346,461) - 31.4%         118,923,902
  Short-Term Securities   Shares      
  Merrill Lynch Institutional Tax-Exempt Fund, 1.71% (j)(k)   84,500,000     84,500,000
  Total Short-Term Securities          
  (Cost - $84,500,000) - 22.4%         84,500,000
  Total Investments (Cost - $667,587,452*) - 180.2%         680,839,973
  Other Assets Less Liabilities - 1.3%         5,084,498
  Liability for Trust Certificates,          
  Including Interest Expense and Fees Payable - (20.9%)         (79,042,154)
  Preferred Shares, at Redemption Value - (60.6%)      
 
 (229,093,618)
  Net Assets Applicable to Common Shares - 100.0%      
$
 377,788,699

*         

The cost and unrealized appreciation (depreciation) of investments as of May 31, 2008, as computed for federal income tax purposes, were as follows:
 
Aggregate cost   $   589,886,317  
Gross unrealized appreciation                   $             18,950,806  
Gross unrealized depreciation      
(6,987,150
)
Net unrealized appreciation   $   11,963,656  

(a)      

FGIC Insured.
 
(b)      

FSA Insured.
 
(c)      

Represents a zero coupon bond or step bond. Rate shown reflects the effective yield at the time of purchase.
 
(d)      

AMBAC Insured.
 
(e)      

U.S. government securities, held in escrow, are used to pay interest on this security as well as to retire the bond in full at the date indicated, typically at a premium to par.
 
(f)      

MBIA Insured.
 
(g)      

Assured Guarantee Insured.
 
(h)      

Radian Insured.
 
(i)      

Securities represent bonds transferred to a tender option bond trust in exchange for which the Trust acquired residual interest certificates. These securities serve as collateral in a financing transaction.
 
(j)      

Investments in companies considered to be an affiliate of the Trust, for purposes of Section 2(a)(3) of the Investment Company Act of 1940, were as follows:
 
Affiliate   Net Activity  
Dividend Income
Merrill Lynch Institutional Tax-Exempt Fund                  
82,200,000
                  $            216,964

6

BlackRock Insured Municipal Income Trust
Schedule of Investments May 31, 2008 (Unaudited)

(k)      

Represents the current yield as of report date.
 
 •

Forward interest rate swaps as of May 31, 2008 were as follows:
 
      Notional      
      Amount     Unrealized
      (000)     Appreciation
Pay a fixed rate of 3.77% and receive a floating            
rate based on 1-week Securities Industry and            
Financial Markets Association (SIFMA) Municipal            
Swap Index rate            
Broker, JPMorgan Chase            
Expires July 2028             $            15,000       $ 76,365
 
Pay a fixed rate of 3.67% and receive a floating            
rate based on 1-week Securities Industry and            
Financial Markets Association (SIFMA) Municipal            
Swap Index rate            
Broker, Citibank NA            
Expires August 2028   $            20,000     378,120
 
Pay a fixed rate of 3.841% and receive a floating            
rate based on 1-week Securities Industry and            
Financial Markets Association (SIFMA) Municipal            
Swap Index rate            
Broker, Citibank NA            
Expires June 2038   $            16,500     126,423
Total         $ 580,908

7

Item 2 – Controls and Procedures
   
2(a) – The registrant’s principal executive and principal financial officers or persons performing similar functions have concluded that the registrant’s disclosure controls and procedures (as defined in Rule 30a-3(c) under the Investment Company Act of 1940, as amended (the “1940 Act”)) are effective as of a date within 90 days of the filing of this report based on the evaluation of these controls and procedures required by Rule 30a-3(b) under the 1940 Act and Rule 13a-15(b) under the Securities Exchange Act of 1934, as amended.
   
2(b) – There were no changes in the registrant’s internal control over financial reporting (as defined in Rule 30a- 3(d) under the 1940 Act) that occurred during the registrant’s last fiscal quarter that have materially affected, or are reasonably likely to materially affect, the registrant’s internal control over financial reporting.
   
Item 3 – Exhibits
   
  Certifications – Attached hereto


Pursuant to the requirements of the Securities Exchange Act of 1934 and the Investment Company Act of 1940, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.

BlackRock Insured Municipal Income Trust

By:
/s/ Donald C. Burke
  Donald C. Burke
  Chief Executive Officer of
  BlackRock Insured Municipal Income Trust
   
Date:   July 18, 2008

Pursuant to the requirements of the Securities Exchange Act of 1934 and the Investment Company Act of 1940, this report has been signed below by the following persons on behalf of the registrant and in the capacities and on the dates indicated.

By:
/s/ Donald C. Burke
  Donald C. Burke
  Chief Executive Officer (principal executive officer) of
  BlackRock Insured Municipal Income Trust
   
Date:   July 18, 2008
   
By:
/s/ Neal J. Andrews
  Neal J. Andrews
  Chief Financial Officer (principal financial officer) of
  BlackRock Insured Municipal Income Trust
   
Date:   July 18, 2008