WASHINGTON (Reuters) - Japanese and South Korean automakers registered the biggest market share gains in the U.S. government's "cash for clunkers" program that ended this week with bankruptcy related inventory shortages hurting General Motors Co GM.UL and Chrysler.

Toyota Motor Corp (7203.T) Honda Motor Co Ltd (7267.T), Nissan Motor Co Ltd (7201.T), Hyundai Motor Co (005380.KS) capitalized on the program's goal of pushing consumers away from gas guzzling sport utilities and pickups, to more efficient cars and trucks, preliminary sales figures showed on Wednesday.

Overseas manufacturers dominate in car sales, while U.S. companies have been stronger in the light truck segment. Cars outsold trucks 2-1 under the "clunker" initiative.

Ford Motor Co (F.N) was the only domestic manufacturer to hold its own in market share compared with its performance so far this year, while GM slipped and Chrysler stumbled noticeably.

GM spokesman Greg Martin said the company, which slowed production significantly during the spring and its early summer bankruptcy, recorded brisk sales of Malibu, Cobalt and other car models in the first weeks of the program.

"We were running thin going into the summer to begin with and, as the program went on, inventory levels play(ed) a part," Martin said.

Ford was the only domestic manufacturer with top-selling models in the "clunkers" program.

Transportation Department figures on the "clunkers" incentive, which offered consumers up to $4,500 when they traded in their older vehicles for more fuel efficient new models, showed on Wednesday that total sales amounted to just under 700,000 with $2.87 billion in rebates.

All sales were to have been completed by 8 p.m. EDT on Monday. Dealers had until Tuesday evening to submit paperwork on transactions. The deadline had been extended one day due to problems with the online network set up by the government to process rebate applications.

According to the figures, Toyota's "clunkers" market share was 19.4 percent, compared with its year-to-date U.S. share through July of 17 percent. Honda captured 13 percent of the "clunkers" market compared with 11 percent for the first seven months of the year.

Nissan accounted for nearly 9 percent of "clunkers" sales compared with a January-July share of 7 percent. Hyundai was the biggest winner with a 7 percent share compared with 3 percent for the year through July.

Ford's "clunkers" sales topped 14 percent, compared with a 15 percent share for the year through July. GM reported 17 percent of "clunkers" business compared with 21 percent from January to July. Chrysler's "clunkers" share was 6.6 percent, compared with 11 percent otherwise.

Chrysler halted production for several weeks during its bankruptcy and gradually brought operations back on line. Its offers the industry's most truck-heavy lineup.

"No one had a six-month supply of cars on the ground," said Jeremy Anwyl, chief executive of Edmonds.com, a consumer resource for sales and other information about the industry. "The inventory situation for Chrysler was more extreme than for others."

Anwyl said consumer preferences for more efficiency at lower prices were influenced by recession and the four-week "clunkers" program and it remains to be seen whether all of the gains made by overseas manufacturers will translate into loyal customers.

"That's the question," Anwyl said, noting that buyers under the "clunkers" program soaked up modestly priced brands.

Japanese, Koreans gain most from cash for clunkers | Special Coverage | Reuters