New Delhi, June 16: The Centre today imposed a 20 per cent customs duty on sugar exports to boost their domestic supply and check prices that are ruling high at Rs 40/kg.

The move comes at a time prices have surged sharply in various commodities, including tomato, wheat and pulses.

"To keep the domestic prices of sugar under check, the government has decided to impose an export duty of 20 per cent on raw, white or refined sugar," the finance ministry said in a release.

The decision has been notified by the Central Board of Excise and Customs.

The duty has been imposed to restrict exports following a sharp rise in global prices. The duty is, however, lower than the 25 per cent proposed by the food ministry.

India, the world's second-largest producer after Brazil, has exported 1.6 million tonnes of sugar so far in the 2015-16 marketing year (October-September).

With retail sugar prices rising to Rs 40/kg from Rs 30/kg six months ago, the Centre has taken various steps to contain prices, including a withdrawal of export-linked production subsidy and an imposition of stock limits on traders.