TOKYO (AP) _ A new, faster bullet train today began service between Tokyo and Osaka, running at a top speed of about 170 miles per hour.

The new bullet train, named ''Nozomi'' or Hope, makes the 320-mile journey between Japan's two largest cities in 2 1/2 hours, 19 minutes faster than the previous fastest train.

The 16-car Nozomi is the first completely redesigned model for the bullet train, officially called the Shinkansen (New Main Line), since it began service in 1964, the year of the Tokyo Olympics.

The Nozomi's maximum speed is 30 mph faster than its predecessors, but below the French TGV's 188 mph.

Engineers say the Nozomi's speed is limited mainly by its track, which runs through hilly terrain and residential areas and was originally designed for maximum speeds of 130 miles per hour. Nearby houses forced designers to reduce noise and vibration.

Instead of the previous bullet-like nose, the Nozomi has a rounded wedge shape that reduces wind resistance and increases traction, according to its designers. The train took $770 million to develop, including large amounts for improvement of the track and signaling system.

Introduction of the Nozomi comes at a time when a Japanese consortium using bullet train technology is bidding against France's TGV and Germany's slower Inter-City Express for a South Korean rail project expected to cost at least $8.3 billion.

The three are also likely to bid for a $11.9 billion railway that Taiwan plans to build by 1999.