NEW YORK (AP) ¿ Shares of YRC Worldwide Inc. climbed sharply in premarket trading Tuesday after the trucking company said it has amended a $950 million credit agreement with lenders, another critical step in the company's struggle to avoid a possible bankruptcy filing. The credit agreement amendment suspends the requirement that the company maintain liquidity of $100 million at all times. The covenant is suspended until Oct. 13. The trucker said in a filing with the Securities and Exchange Commission that JPMorgan Chase Bank, among other lenders, will continue to provide YRC with a $950 million senior revolving credit facility, including portions available for borrowing and for letters of credit, and a senior term loan of about $111.5 million. The company has amended other credit agreements, sold real estate, cut thousands of jobs and trimmed wages among existing workers to stay afloat. Stifel Nicolaus & Company analyst David Ross on Monday reiterated his "Sell" rating on shares of YRC Worldwide. In a note to clients, he said the amendment was no surprise and the company should still be challenged to maintain adequate liquidity after Oct. 13 if there are no further amendments. Ahead of Tuesday's market open, shares of YRC advanced 39 cents, or 17.5 percent, to $2.62. The stock has ranged from 89 cents to $19.61 over the past year.