DETROIT -- Toyota Motor Corp. has offered to buy back Tacoma pickup trucks with irreparable rusted frames and to extend the warranty on more than 800,000 of the vehicles in North America, Reuters reported.

Toyota is offering to buy back Tacoma trucks built between 1995 to 2000, with frames so badly rusted they cannot be repaired, at one and a half times the suggested retail price for a vehicle in excellent condition as calculated by Kelly Blue Book.

In addition, the Japanese automaker will extend the warranty on Tacoma frames from the standard 3-years or 36,000 miles to 15-years with unlimited mileage for the rust problem.

Toyota said it expected that a small number of the 813,000 trucks covered by the action would have frames so rusted it would require a buyback. Those were more likely to be in areas with heavy snow that are exposed to road salt, it said.

The cost of the sweeping buyback and extended warranty program was not clear.

The Tacoma frame rust appears to stem from a production problem that kept the components from getting enough undercoating when they were manufactured, the automaker said.

The trucks were built at the New United Motor Manufacturing plant in Fremont, Calif., which is a joint venture started in 1984 by Toyota and General Motors.

The unusual customer-service action comes amid slumping U.S. truck sales and at a time when the world's No. 1 automaker faces new scrutiny after a string of glitches that has threatened to mar its industry-leading reputation for quality.

A Toyota letter to its North American dealers outlining the terms of the buy back and other company documents pertaining to the problem with Tacoma frames rusting were posted on the Web site of the Washington, D.C.-based Center for Auto Safety. Letters to Tacoma customers began going out in March.