Arco’s Anderson was sued over his oil purchases.

Robert O. Anderson, the retired chairman of Atlantic Richfield, was named in a shareholders’ suit accusing him of using inside information to acquire valuable deep-drilling oil rights from Arco at far less than their actual value. The suit, filed in Los Angeles Superior Court by stockholder Rodney B. Shields, claims that Anderson was the only bidder who knew the West Texas deep-drilling rights were available when the company was seeking bids on a package of 900 oil properties. Arco confirmed that but said it doesn’t think “the value of the deep rights obtained are material to the total value of the package sold.” First Boston conducted the bidding and “assured us the process was competitive,” Arco said.