Security Pacific Corp., Los Angeles, said its...

Security Pacific Corp., Los Angeles, said its Security Pacific Automation Co. unit has agreed to acquire Summit Information Systems Corp., Corvallis, Ore., for an undisclosed price . . . Atari Corp., Sunnyvale, said it has purchased the creditor position of about $32 million in the Federated Group Inc., its wholly owned consumer electronics retailing chain, from five banks led by Security Pacific National Bank . . . Santa Cruz, Calif.--based Plantronics Inc. said it would not pay its regular quarterly dividend of 4 cents a share for the fourth quarter of fiscal 1988.