[ by Howard Haykin ] Barclays announced plans on Monday to sell its $6 billion stake in investment management firm BlackRock, reportedly moving before a new banking regulation framework takes effect.  Barclays owns 19.6% of BlackRock.  According to Barclays, BlackRock agreed to buy back as much as $1 billion of its stock from Barclays as part of the transaction. Basel III and Volcker Rules Come into Play. In the coming years, banks will be required to adapt to the latest rules from the Basel Committee on Banking Supervision, known as Basel III. The regulations would make it more costly for Barclays to hold a stake in an investment firm like BlackRock because it would have to set aside capital against the stake to cushion itself against any decline in the value of that holding. But Why Sell Now? Banks are selling assets to increase their capital buffers amid the regulatory changes.  Barclays, based in London, is also in the middle of a reorganization aimed at improving profitability. The bank cut jobs and has been exiting business operations that did not meet certain targets.  Investec analyst Ian Gordon, based in London, wrote in a note to investors that it was "reasonable" for Barclays to sell the BlackRock stake ahead of the introduction of Basel III. Barclays acquired the stake in BlackRock in 2009 for when it sold Barclays Global Investors to the company for about $13.5 billion in 2009.  The acquisition of the Barclays unit was the biggest to date for BlackRock, which had $3.7 trillion in assets under management as of 3/31/12. BlackRock was co-founded in 1988 by Laurence Fink, mainly as a bond house;  since then it has grown through acquisitions into one of the world’s biggest asset management companies. After the acquisition of Barclays Global Investors, the Barclays CEO Robert Diamond Jr., and his predecessor, John Varley, became members of BlackRock’s board.  Barclays had to write down the value of its BlackRock investment in September 2011 after it declined. For further details, go to:   [Dealbook, 5/21/12].