General Motors regained its title as the world\'s top-selling carmaker from Japanese rival Toyota Motor in 2011, but the US company faces a challenge to stay on top this year as Toyota rebuilds its disaster-struck business. GM, bouncing back from bankruptcy less than three years ago, said on Thursday it sold 9.026 million vehicles globally last year, up 7.6 per cent from 2010, with its Chevrolet brand setting a sales record of 4.76 million vehicles. The Detroit-based car maker\'s return to the top slot comes after its 2009 taxpayer-funded bankruptcy restructuring allowed it to cut its spiralling legacy costs. It also comes as Toyota\'s sales fell an estimated six per cent in 2011 to 7.9 million vehicles, hit by severe production cuts following an earthquake, tsunami and nuclear crisis in Japan and deadly floods in Thailand. The Japanese carmaker is ramping up production to rebuild depleted inventory and will add output capacity in emerging markets such as Brazil and China this year. But analysts said it also faced stiffer competition as rivals step up their game. \"Toyota\'s biggest problem is that even without the natural disasters, its sales weren\'t exactly growing,\" JP Morgan auto analyst Kohei Takahashi said. \"The ranking is not that important, but they need a convincing strategy to boost their sales,\" he said, adding that Toyota was behind rivals such as Nissan Motor in rolling out small cars for emerging markets. Toyota has lagged the sharper sales growth at rivals such as Nissan and Hyundai Motor because of a relatively slow push into emerging markets as it scrambled to meet runaway demand in mature markets in the past decade. In a bid to catch up, Toyota is adding factories in Brazil, China, Thailand and elsewhere, aiming to sell half its cars in emerging markets by 2015, up from around 40 per cent now. Bumps in the road Toyota\'s 2011 worldwide sales tally included listed subsidiaries Daihatsu Motors and Hino Motors, and it put the carmaker behind Volkswagen AG, which sold 8.16 million vehicles last year. It also just trailed the 8.03 million sold by Renault and partner Nissan, though this number includes the 638,000 cars sold by Russia\'s AvtoVAZ, in which the French car maker owns a minority 25 per cent.