Buttes failed to make an interest payment.

The Oakland-based firm said it did not make a Sept. 15 payment on 16.5% senior subordinated debentures due 1994. The company, which has reported losses in each of the last three years, also reported that a lawsuit has been filed against it seeking repayment of $10 million loaned to it under a credit agreement. Buttes Oil & Gas said the lender was a private corporation but refused to identify it.