Atlantic Richfield sued a New York oil broker.

The lawsuit, filed in U.S. District Court in New York, claims that Triad Petroleum and its president, Joseph V. DiMauro, acted without proper authority from Arco while negotiating a deal with Amoco Corp. Arco said it discovered that its name had been used in the deal after Amoco sought $815,000 from Arco for failing to follow through on the agreement. The suit seeks to have Triad pay for any costs associated with the transaction.