New Delhi, Oct. 14 -- With no global automaker showing interest so far in India's flagship plan to promote electric car manufacturing, the government is considering extending the scheme's 21 October deadline, two people aware of the matter said.

The likely extension to the scheme, often called the Tesla scheme for its attempt to attract the US-headquartered electric vehicle (EV) giant to India, lays bare the difficulty of converting policy ambition and generous tax breaks into firm investment commitments.

Under the scheme to promote manufacturing of electric passenger cars in India (SPMEPCI), manufacturers investing $500 million in the country will get a massive import duty cut on fully-built models. If the company fulfils the investmen...