Assets of the nation’s 456 money market...

Assets of the nation’s 456 money market mutual funds fell $2.03 billion to $278.64 billion in the latest week, the Investment Company Institute said . . . CBS Inc. has entered into a definitive agreement to acquire two Detroit radio stations--WWJ-AM and WJOI-FM--from Federal Broadcasting Co., a subsidiary of Federal Enterprises Inc., for $58 million . . . The Justice Department is investigating a revised joint operating agreement involving the Miami Herald and the Miami News, a department spokesman said, to determine whether there might be a violation of antitrust laws.