The Justice Department said that Pan Am’s...

The Justice Department said that Pan Am’s plan to sell its Pacific routes to United Airlines “could have an adverse effect on competition” and that the proposed sale will be investigated further . . . Knight-Ridder Newspapers said it has purchased 9.5 million shares of its common stock from the estate of the late John S. Knight and from a trust established by Knight . . . MCA said it has completed the previously announced acquisition of a 63% stake in LJN Toys . . . The Investment Company Institute reported that the assets of the nation’s 343 money-market mutual funds nudged up $22.6 million in the week ended May 15.