DALLAS (AP) _ A Southwest Airlines plane had engine trouble shortly after departing and had to return to the airport.

Southwest spokeswoman Marilee McInnis says the flight had departed from Dallas bound for St. Louis, Mo. at 4:20 p.m. Saturday. Shortly after, the aircraft's pilot realized there was a problem with one of the engines and the plane returned to Dallas.

McInnis says it landed safely at Love Field around 5 p.m. and was taken out of service. The 137 passengers on the flight were being transferred onto a new aircraft to continue their travel to St. Louis.

Copyright 2008 The Associated Press.