Federal banking regulators have announced that New York City's Harlem Savings Bank has taken over the failing Central Savings Bank -- the second time in a month a state savings bank was rescued from financial collapse.

The chairman of the Federal Deposit Insurance Corporation (FDIC), William Isaac, said the merger would cost the government about $ 64 million in assistance, compared with some $ 260 million if Central were forced to close.

The Harlem, with six offices in Manhattan and two in Nassau County, had assets of $ 830 million, now raised to about $ 1.6 billion.

The merger, effective Friday, makes the Harlem the city's 16th largest and the state's 18th largest mutual savings institution.

The FDIC, which insures banks and tries to find partners for those in trouble, has also been seeking merger partners for the New York Bank for Savings, the city's third largest, and the Union Dime Savings Bank, now the city's 19th largest, sources said. Central was the 24th largest.

Many of the savings banks are having difficulty because the yields they get on loans -- most of which are mortgages -- are lower than the interest they have had to pay to obtain funds and on some deposits such as six-month money market certificates.

Last month the Greenwich Savings Bank, with assets of $ 2.5 billion, was merged with the Metropolitan Savings Bank.