The yen slipped into the 146 zone against the U.S. dollar on Wednesday morning, a level unseen in 24 years and weaker than it was when Japan intervened in the currency market last month. Japanese finance authorities stepped into the market on Sept. 22 to support the yen after it depreciated to 145.90. It was their first yen-buying, dollar-selling intervention since 1998. The yen broke through the 146 barrier shortly after the dollar fetched 145.87-92 yen at 9 a.m., compared with 145.81-91 yen in New York and 145.63-64 yen in Tokyo at 5 p.m. Tuesday. The euro was quoted at $0.9698-9702 and 141….