The yen gave up further ground against the dollar Tuesday amid concerns over the ailing Japanese economy and financial crises in Southeast Asian countries.The yen fell to 134.38 yen to the dollar at one point, its lowest in almost six years, before settling at 133.57-60 yen at 5 p.m., compared with Monday's late quotes of 132.83-86 yen.Reflecting a continuing switch away from the yen and into the dollar, "Japan selling" is gathering momentum, brokerage officials said. A reported comment overnight by U.S. Treasury Secretary Robert Rubin that a strong dollar is in the interest of the U.S. undermined Japanese monetary authorities' efforts to stem the yen's further fall, they said.The Rubin comment encouraged speculator attacks on the yen, and the dollar briefly hit 134.10 yen in New York trading Monday. There was talk that the Bank of Japan sold dollars for yen, helping the Japanese unit recoup some of its earlier losses.The central bank's unconfirmed move followed its officially publicized interventions in mid-December. Prime Minister Ryutaro Hashimoto, speaking to reporters at his official residence, expressed concern over the yen's weakness, blaming it on the Southeast Asian currency turmoil. Sharp drops in the value of Asian currencies dragged the yen down, Hashimoto said.In a separate news conference, Finance Minister Hiroshi Mitsuzuka declared that he would soon announce emergency measures to address the stock market's decline. Mitsuzuka's comment helped the Tokyo stock market recoup much of its earlier losses.The 225-issue Nikkei average ended 60.44 points lower at 14,896.40, after losing nearly 130 points earlier in the day.