Braniff agreed in principle to lease 20...

Braniff agreed in principle to lease 20 new Boeing 737-300 jet aircraft from Guiness Peat Aviation in a $600-million deal. Delivery is scheduled between June, 1990, and June, 1992 . . . H. J. Heinz Co. authorized a 2-for-1 stock split and increased the dividend on common stock to 42 cents from 36 cents. The dividend applies to shares held before the 2-for-1 stock distribution and is payable Oct. 10 to shareholders of record on Sept. 21 . . . Bentonville, Ark.-based Wal-Mart Stores Inc. said it has acquired Cullum Cos.’ interest in the Hypermart USA joint venture between the two firms, for an undisclosed price . . . Riverside Group Inc. of Jacksonville, Fla., said it completed the purchase of National American Life Insurance Co. of California from Los Angeles-based H. F. Ahmanson & Co. for $27.5 million . . . Ampco-Pittsburgh Corp. said it had increased its stake in Midway Airlines Inc. to 9.6% and indicated that it was still considering a takeover attempt.