The UST/TCW Senior Mortgage Securities Fund LP, which completed its initial closing on Sept. 30, will return capital to investors and liquidate the fund after the ouster of its former investment chief, Jeffrey Gundlach, Los Angeles-based TCW said yesterday. The fund was raised for participation in the Public-Private Investment Program, which combines private contributions with government capital and loans to buy troubled securities from banks. TCW was one of nine money managers selected in July to oversee investments in PPIP. Before yesterday, funds participating in the program had raised about $6 billion of equity capital from private investors, which the government has matched. The Treasury also provided $12 billion of debt capital, bringing the funds’ purchasing power to $24 billion. The other firms include New York-based BlackRock Inc., Invesco Ltd. in Atlanta, an affiliate formed by Baltimore-based Legg Mason Inc. and Los Angeles-based Oaktree Capital Management LP.