Renault, which already owns 36.8 percent of Nissan, said it will spend 215.9 billion yen ($US1.6 billion) to increase its stake in Japan's third largest car maker to 44.4 percent tomorrow to expand their alliance, according to Bloomberg News. Renault will buy the extra Nissan shares at 400 yen each, as agreed in 1999 when it acquired its initial stake, Bloomberg said, adding that the companies said in October that they would strengthen their ties, with Nissan buying 15 percent of Renault and the French firm raising its Nissan ownership a year earlier than anticipated.