An investment group said it holds a...

An investment group said it holds a 5.7% stake in Tosco Corp.’s outstanding common shares . . . Panatech Research & Development said it has acquired Adamas Carbide Corp. of Kenilworth, N.J., from S.W. Industries of Providence, R.I., for $7.4 million . . . Dallas investor Harold Simmons said his offer to purchase NL Industries for $900 million expired Thursday and will not be extended . . . Lockheed said its $60-per-share tender offer for Sanders Associates common stock has been extended until midnight EDT, Aug. 13 . . . The board of Converse, the athletic footwear maker known for its canvas All Star high-tops, approved a $28-a-share takeover offer worth about $131 million by Interco Inc., maker of Florsheim shoes . . . The Investment Company Institute reports that the assets of the nation’s 363 money-market mutual funds rose $507.6 million in the week ended Aug. 6.