Tokyo: Japanese automaker Toyota Motor Corp. sold over 10 million units worldwide in 2015 and the sale, beating Volkswagen and General Motors, earned the giant carmaker the world's top car-seller spot for the fourth straight year, it said on Wednesday. The Japanese carmaker sold 10,151,000 units last year, including sales of its subsidiaries of Daihatsu Motor Co. and Hino Motors Ltd. Toyota's two major rivals -- Volkswagen and General Motors -- failed to reach the 10 million-unit threshold. Toyota's total sales for 2015 marked a 0.8 percent decline from the previous year, but robust demand overseas, such as in Northern America, helped its global sales boom, while domestic performance was weak relatively. The Japanese company has aimed to sell 10,114,000 units worldwide, according to the report. Meanwhile, the automaker is reportedly eyeing possible cooperation with another Japanese carmaker Suzuki Motor Corp. to meet increasing demand for compact cars in emerging markets such as India. The two companies are exploring the possibility of joining hands in safe driving technology and eco-friendly cars, with cross-shareholdings an option, Japan's Kyodo News reported on Wednesday citing unnamed sources. The tie-up would help Toyota boost its market share in India, said the report, but added that the two have said in separate statements that they were not discussing a potential partnership.