Portfolio Update

BLACKROCK COMMODITIES INCOME INVESTMENT TRUST PLC

All information is at 31 March 2010 and unaudited.

Performance at month end with net income reinvested

                          One    Three      Six       One      Since    
                        Month   Months   Months      Year     Launch*  
                                                                                
Net asset value          9.3%    11.3%    20.8%     63.9%      71.2%             
Share price             16.7%    13.3%    23.8%     57.8%      72.4%             

Sources: Datastream, BlackRock
* 13 December 2005

At month end                                                                   
Net asset value - capital only:                    138.55p                     
Net asset value - cum income**:                    139.16p                     
Share price:                                       142.75p                     
Premium to NAV (capital only):                        3.0%                     
Net yield:                                            3.9%                     
Gearing - cum income:                                 2.0%                     
Revenue per share:                                   0.61p                     
Total assets:                                      £106.92m^                   
Ordinary shares in issue:                       75,325,662                     

**Includes net revenue of 0.61p.
^includes current year revenue.

                          % of Total                                 % of Total
Sector Analysis               Assets       Country Analysis              Assets
                                                                               
Integrated Oil                  27.1       USA                             20.5
Diversified                     16.2       Global                          20.5
Exploration & Production        15.8       Canada                          13.0
Copper                           9.5       Europe                          12.9
Coal                             5.6       Asia                            12.4
Oil Services                     4.7       Latin America                    8.8
Iron Ore                         3.6       South Africa                     7.1
Aluminium                        3.4       Australia                        3.8
Fertiliser                       3.3       China                            1.6
Gold                             2.8       Africa                           0.9
Nickel                           2.5       Current liabilities             (1.5)
Platinum                         2.5                                      -----
Zinc                             1.8                                      100.0
Tin                              1.5                                      =====
Distribution                     1.2                                           
Current liabilities             (1.5)                                           
                               -----                                           
                               100.0                                           
                               =====                                           

Ten Largest Equity Investments (in alphabetical order)                         
                                                                               
Company                                   Region of Risk                       
                                                                               
Anadarko Petroleum                        Global                               
BHP Billiton                              Global                               
BP                                        Global                               
Freeport McMoRan                          Asia                                 
Kumba Iron Ore                            South Africa                         
Niko Resources                            Asia                                 
Occidental Petroleum                      USA                                  
Rio Tinto                                 Global                               
Statoil                                   Europe                               
Vale                                      Latin America                        

Commenting on the markets, Richard Davis, representing the Investment Manager
noted:

March was a strong month for mining commodities with base metals reaching their
highest levels since August 2008. Copper rose to US$7,878/t, a gain of 8.3% (in
US Dollar terms) on the month. With increased demand from China and evidence
that demand from the OECD (Organisation for Economic Co-Operation and
Development) nations is improving, the fundamentals for copper look strong as
mine supply appears to be constrained for the foreseeable future. Nickel also
rallied strongly, closing the month up 18.3% at US$24,960/t. Nickel has been
the best performing base metal in 2010 with a year-to-date return of more than
35%. The metal continues to benefit from the economic recovery while around 20%
of global output remains offline. In the precious metals space, gold prices
closed the month largely unchanged, while platinum gained 7.3%. The key
developments during the month were in bulk commodities. In the iron ore market,
the difference between the annual contract price and the spot price widened
significantly in 2009/10 and is currently trading more than 100% above the
benchmark price. This can largely be attributed to increased demand from
Chinese steel producers and the signs of tentative recovery in Western World
steel production. Consequently, the iron ore producers are leading the industry
away from the annual contract pricing system to shorter-term, market based
prices. At the end of the month, BHP Billiton reported that it had reached such
an agreement with a number of its Asian customers. This is positive news as it
will enable the producers to capture the significant premium at which spot
prices have been trading. Importantly, the new contract also captures any
freight differential that may exist between it and Brazilian supply.

In the energy sector, oil prices gained 5.2% to finish the month at US$83.5/Bbl
(WTI) after demand for oil improved in the US. Meanwhile, the Henry Hub natural
gas prices declined -20.1% to US$3.8/mcf. This dramatic decline is a result of
the increased US gas drilling which has fed extra supply into the markets. The
members of OPEC (Organisation of the Petroleum Exporting Countries) met in
Vienna in March. Having noted the recent range bound level of oil prices, they
expressed an expectation that stronger demand for oil in 2010 would be offset
by extra supply from outside OPEC. They agreed to leave their production quotas
unchanged.

Latest information is available by typing www.blackrock.co.uk/its on the
internet, "BLRKINDEX" on Reuters, "BLRK" on Bloomberg or "8800" on Topic 3 (ICV
terminal).

26 April 2010