TOKYO (Reuters) - Japan's Toyota Motor Corp. outsold General Motors Corp. by around 90,000 vehicles in the first quarter, moving a step closer to unseating its U.S. rival as the world's biggest automaker.

Toyota has been widely expected to challenge 99-year-old GM this year for the top spot in global sales -- a position the Detroit behemoth has held for 76 years -- but the milestone came surprisingly early, industry watchers said.

Both companies reported record sales for January-March, but Japan's top carmaker inched past GM as it ate into the U.S. group's market share on its home turf.

Toyota, maker of the Camry sedan -- the United States' most popular car -- said on Tuesday its global vehicle sales rose 9 percent to 2.35 million units in the quarter.

The tally includes cars sold under the Lexus luxury brand and the youth-oriented Scion badge, as well as vehicles from units Daihatsu Motor Co. and Hino Motors Ltd..

GM, which sells cars and trucks under a dozen brands including Chevrolet, Buick, GMC, Cadillac, Opel and Saab, sold 2.26 million units during the same period, for a 3 percent rise.

``Toyota has had aggressive new model introductions all over the world,'' said Koji Endo, an auto analyst at Credit Suisse Securities in Tokyo.

``It's achieved growth everywhere in the world, whereas GM's significant growth has only been in China,'' he said.