The bankruptcy lawyers who handle the biggest U.S. corporate restructurings responded with hostility yesterday at a public hearing by the U.S. Trustee Program examining their professional fees, which can reach hundreds of millions of dollars at the expense of creditors, Reuters reported yesterday. The top billers said that the market values their experience and knowledge in restructuring companies such as Chrysler Group LLC. Critics say that it is because managers of bankrupt companies are less aggressive than other clients in asking for discounts. The U.S. Trustee Program wants to know whether law firms inflate their rates in bankruptcy cases - for example, by using more lawyers than necessary, or by dragging their feet - knowing they are unlikely to be challenged by the court.