Subprime mortgage servicers across the board improved their cash flow efficiency in the second quarter by stepping up liquidations and modifications, Moody’s Investors Service says.

The firm’s cash flow efficiency metric rose to 0.29 in the second quarter from 0.27 in the first. The metric measures the amount of cash that servicers collect on modified and liquidated loans as a proportion of their realized losses from principal on modified loans and property liquidations.

GMAC was one of the top performers, according to Moody’s (see chart below). Its servicing efficiency improved despite the company’s financial difficulties. The uncertainty regarding GMAC ownership — its corporate parent, Residential Capital Funding, filed for bankruptcy in May — has not led to the kind of staff attrition or performance deterioration typical in financially distressed servicers.

Ocwen Financial Corporation (OCN), which just purchased Homeward Residential from WL Ross & Co., has proven itself able to handle its rapid portfolio growth. Efficiency gains in its own portfolio and acquired ones from Saxon and Litton is helping Ocwen.

Bank of America (BAC) improved its servicing efficiency in recent quarters by executing a large volume of short sales. Since the states attorneys’ general settlement with major servicers, which took effect in April, BofA has resolved more delinquent loans through short sales than JPMorgan Chase (JPM), Wells Fargo (WFC), CitiMortgage (C) and Ally Financial combined.

BofA continues to boost the portion of highly delinquent loans it sub-contracts to special servicers with smaller, more manageable portfolios.

Property liquidations among servicers rose to their highest level over the past several years, accounting for 2.6% of delinquent balances, up from 2.2%, Moody’s found. The average monthly modification rate increased slightly, lowering the number of delinquent loans in the pipeline.

Aurora, awaiting the transfer of its portfolio to Nationstar (NSM), experienced the sharpest decline in efficiency. Moody’s cites Nationstar’s acquisition of Aurora’s portfolio as a possible cause of the drop in the latter’s second quarter efficiency. Nationstar didn’t disclose its post-transfer human resources plan until May, two months after announcing the purchase.

“Employee’s uncertainty regarding their employment is a possible factor behind the decrease in loan modifications,” Moody’s said.