Original sentence: It currently has codeshare agreements with American Airlines, Continental Airlines, Delta Air Lines, Northwest Airlines (which is to be gradually absorbed into Delta throughout 2009-2010 due to the merger), PenAir, and Era Aviation
Edited sentence: It currently has codeshare agreements with American Airlines, Continental Airlines that will end October 25th, 2009, Delta Air Lines, Northwest Airlines (which is to be gradually absorbed into Delta throughout 2009-2010 due to the merger), PenAir, and Era Aviation