Maruti Suzuki India Ltd., the country’s biggest carmaker, is planning to plow 350 billion rupees ($4.2 billion) into a new plant in the western state of Gujarat.

The factory will add 1 million vehicles per year to the company’s existing output of 750,000 units in Gujarat, said Toshihiro Suzuki, president of Suzuki Motor Corp., at the biennial investors’ gathering Vibrant Gujarat on Wednesday.