The BlackRock Solutions advisory group was given the contract to oversee the assets and before that WCAS Fraser Sullivan Investment Management administrated the loans, which are generally related to high-yield, high-risk companies, reports Bloomberg.
Bloomberg reported a Lehman spokeswoman Kimberly Macleod as saying, "The manager was changed by mutual agreement between the company and the prior manager due to a shift in strategy."
Lehman had announced in March 2012 that it emerged from bankruptcy and switched to BlackRock as it battles to accumulate $53bn until 2016 to pay back the creditors.
In August 2011, the bankruptcy court allowed WCAS Fraser Sullivan to oversee $5.3bn of the debt, including $1.5bn of unfunded loan commitments.