Delta Air Lines announced that it would purchase United's JFK-London route authority for up to $21 million, pending approval from the Department of Transportation and bankruptcy court (Delta is still in Chapter 11).
Delta has been trying unsucessfully to fly this route for over a decade. It has an international hub at JFK and flies to many European destinations from the airport but has yet to serve London. If all goes well, it plans to start its first service to London's Gatwick (not Heathrow) airport later this year and add flights next year.
Of course, if the route wasn't profitable for United then I would see reason to sell it off. But hopefully this won't turn out to be a repeat of the 1991 disaster where TWA sold it's JFK-London Heathrow authorities to American Airlines for some quick cash. In the short term, the deal paid off, but TWA really made lots more money on the route than they sold it for, and American pulled off a great deal at TWA's expense.
Also of note: United flew the route from JFK to London's Heathrow Airport, which is the city's primary international gateway and on the shortlist of the world's busiest airports. But under some law, only United and American are allowed to fly into Heathrow, since they purchased their route authorities from Pan Am and TWA, respectively. The other US carriers - like Delta, for example - have to go into Gatwick.