By Carolyn Cohn LONDON (Reuters) -U.S. asset management group BlackRock said on Friday it was reducing leverage in so-called liability-driven investment (LDI) funds at the centre of chaotic market conditions for British pension funds this week, to protect its clients’ capital. British government bond prices slumped by their most in decades following finance minister Kwasi Kwarteng’s first fiscal statement last Friday, threatening the stability of the country’s pension funds and forcing the Bank of England to intervene on Wednesday. “As a result of the extreme volatility in the gilts market thi…