Placid Oil Co. officials said they aren't surprised that a committee of creditor banks has submitted a reorganization plan asking that the company be sold to pay off more than $700 million in debts. But officials at Dallas-based Placid, which is owned by the Hunt brothers, said they will oppose the plan. The plan was submitted Thursday to U.S. Bankruptcy Judge Harold Abramson just two days after the mammoth trusts of Nelson Bunker Hunt and Lamar Hunt filed bankruptcy petitions. The creditors' plan, which is supported by 16 of the 17 banks with loans to Placid, seeks to offer the oil company to the highest bidder. But it also includes a guarantee that the creditor banks will buy the company if a buyer can't be found.