TULSA, Okla. (AP/CBSDFW.COM) — American Airlines workers in Tulsa say they are stepping up efforts to save hundreds of local jobs that could be on the bankrupt company’s chopping block.

On Tuesday, workers with the Transport Workers Union were printing up 500 yard signs touting their campaign’s website, www.isupportamericanjobs.com , where visitors are asked to sign an online petition as a show of support. More than 15,000 people have signed so far.

The struggling Fort Worth-based company filed for bankruptcy protection on Nov. 29 after posting $11 billion in losses since 2001.

Corporate executives have said the company plans to lay off about 13,000 employees companywide, including thousands of mechanics, flight attendants, pilots and management staff as it goes through reorganization.

(Copyright 2012 by CBS Local.  The Associated Press contributed to this report.  All Rights Reserved.)