In a letter to employees on Thursday, Parker said, "we continuously consider strategic options for our airline and over the past several months, we have studied a transaction with United. However, those talks have not progressed to a merger agreement, and for the foreseeable future we intend to remain a standalone carrier. "As I have said many times, it is not necessary for us to be direct participants in a merger because the entire industry benefits when consolidation occurs," Parker added. "I am sure some 'industry experts' will suggest that US Airways will be strategically harmed if United now chooses to merge with Continental. They will be wrong. "Should our competitors choose to merge and help create a more stable airline industry, our independent airline will only become stronger," Parker said. In early afternoon trading, US Airways shares were down 30 cents to $6.46. United shares were down 15 cents to $21.28. Continental shares were down 13 cents to $21.33. -- Written by Ted Reed in Charlotte, N.C.