United Airlines and Continental Airlines announced today that members of each carrier’s frequent flyer program who have earned elite status will receive unlimited, complimentary domestic upgrades on flights operated by both airlines when space is available.

Continental’s elite-level frequent flyers also will have complimentary access to United’s Economy Plus® seating, offering additional legroom near the front of the economy cabin. United’s elite-level frequent flyers will have complimentary access to Continental’s premium seating as well.

These new benefits will begin to roll out in mid-2010.

Unlimited domestic upgrades and preferred economy class seating for elite-level frequent flyer members are the latest additions to the suite of benefits available to United and Continental customers since the two carriers announced a wide-ranging global partnership in June 2008 and since Continental joined the Star Alliance October 27 – benefits that include new access to dozens of cities around the world, recognition of elite status, and the ability to accrue and redeem miles on each other’s flights.

“The partnership between United and Continental means more comfort and better rewards for our most loyal customers,” said Graham Atkinson, president of Mileage Plus. “While our elite-level customers enjoy significant benefits on Continental through its membership in Star Alliance, we are delighted to build on those benefits to provide travelers the best our industry has to offer.”

“Continental and United have highly complementary networks that cover the map for business travelers,” said Mark Bergsrud, Continental’s senior vice president marketing programs and distribution. “This announcement is part of our ongoing plan to deliver frequent flyer benefits that offer the best overall solution for the traveler who wants extra space and comfort across the network.”