Creditors of bankrupt Lyondell Chemical Co asked a US judge to expand an investigation by a court-appointed examiner to ensure the petrochemicals company is fairly evaluating proposals from potential suitors. An official committee of unsecured creditors wishes to ensure that potential bidders like India's Reliance Industries have a chance to compete against a reorganization plan offered by a group of the company's senior creditors, including current owner Access Industries and private investment firms Ares Management and Apollo Management. Lyondell's unsecured creditors said in court papers they believe Reliance's offer is superior to the one proposed by Access, Ares and Apollo. The unsecured creditors also questioned the propriety of US$440 mln of "adequate protection" payments made to the company's senior lenders since the company filed for bankruptcy in January. They argued the examiner should investigate why Lyondell is paying the money, which cannot be recovered.