TOKYO — Former Japanese Prime Minister Ryutaro Hashimoto, who stood up to the United States in trade negotiations and helped diffuse tensions over U.S. military bases in Japan, has died. He was 68.

Hashimoto, who was prime minister from January 1996 to July 1998, died Saturday at the International Medical Center of Japan in Tokyo, said hospital spokesman Hajime Takayama. He had been in critical condition after suffering abdominal pain and undergoing surgery to remove a large part of his intestines.

His son, lawmaker Gaku Hashimoto, said his father died from multiple organ failure.

Hashimoto's star rose when he demonstrated rare toughness against Washington in a bitter auto sales dispute as trade minister in 1995. But his political career ended under the shadow of controversy.

A political donation scandal prompted him to resign last year as head of what was then the largest faction in the ruling Liberal Democratic Party. He retired from politics in September, citing poor health.

"Mr. Hashimoto had a vision of our country in the 21st century. ... I'm deeply saddened by the news of the passing of an outstanding leader," Prime Minister Junichiro Koizumi said in a statement, noting Hashimoto's efforts to streamline government agencies, stabilize the financial system and restructure the Japan-U.S. security alliance, Kyodo News agency said.

Hashimoto, known for his slicked-back hair and chain-smoking, was first elected as a member of the lower house of parliament in 1963. His policymaking and analytical skills won him several top Cabinet positions, including trade, finance and transportation ministers.

"I'm shocked by the sudden news and filled with sorrow," LDP Secretary General Tsutomu Takebe told Kyodo News. "He was one of the party's best policy experts and the man of principles."

Hashimoto, who is from Japan's southwestern state of Okayama, also won praise for his diplomacy in settling several thorny issues.

In 1997, he helped quell opposition to U.S. military bases on the southern island of Okinawa, arranging to return to the local government land that had been leased to the Marines. He also promised aid to shore up Okinawa's struggling economy.

But his toughness -- he was an expert swordsman and a mountain climber -- also got him into trouble.

Like Koizumi, Hashimoto supported visits to a controversial Tokyo shrine dedicated to the war dead, including those hanged for crimes against humanity during World War II. The visits have triggered protests from China and other nations invaded by Japan. In recent years, however, Hashimoto supported efforts to improve Japan-China relations.

Hashimoto's term in office was dominated by efforts to mend Japan's ailing economy, which caused his approval ratings to slump. He made a series of unpopular fiscal decisions, including an increase in the national sales tax and a bailout for housing loan companies awash in bad loans. He also proposed a billion-dollar tax cut package and fresh government spending.