Mangalore Refinery and Petrochemicals Ltd said it will begin processing crude from Cairn India's Rajasthan fields on Friday, reducing the refiner's imports of low-sulphur crude.

Managing director UK Basu said MRPL would process 200,000 tonnes or nearly 1.43 million barrels of Rajasthan crude by the end of the fiscal year next March, and the government-allocated volume is set to double to 2.87 million tonnes in 2010/11.

"We will be getting the first parcel tomorrow. It is about 29,000 tonnes (208,000 barrels)," Basu told Reuters.

Cairn India, a subsidiary of UK-based Cairn Energy Plc, began pumping crude in late August from its Mangala oil field in the Rajasthan block, the first major crude oil discovery in the energy-hungry nation in two decades.

Basu said MRPL would blend the oil with Mumbai High crude produced by state-run explorer Oil and Natural Gas Corp from its western offshore fields. MRPL, majority owned by ONGC, runs a 194,000 barrel-per-day refinery in southern India.

"We cannot process it (Rajasthan crude) neat... it will reduce our imports of low sulphur crude like Nile Blend, Sokol and Nigerian grades which we import from spot market," he said.

MRPL often buy buy Nile Blend from ONGC, which has a stake in Sudanese oil fields. It has also bought three Sokol parcels from ONGC since December 2006.

"We have been allocated 0.4 million tonnes (of Cairn oil) for next year, but after processing it for few months we will get an estimate as to how much can we process in a year at our refinery," he said

Cairn India holds a 70 per cent stake in the RJ-ON-90/1 block in western India, while ONGC holds the balance.