India's Reliance has submitted the best offer into Sri Lanka's tender to buy gas oil and gasoline for June 16-17 delivery, a company source said on Thursday.

Reliance had offered to sell 25,000 tonnes of gas oil to Sri Lanka's state-owned Ceylon Petroleum Corp (Ceypetco) at a premium of 81 cents per barrel over Singapore quotes, said the source.

Reliance had also offered to sell 10,000 tonnes of 90-octane gasoline at a premium of $1.56 a barrel over the same benchmark, and 5,000 tonnes of 95-octane gasoline at a $1.74 per barrel premium.

"This is a combined cargo. Reliance on the whole submitted the best offer," said the company source.

Two other offers came from Petroplus Dubai and Vitol. The premiums for gas oil were heard at 80 cents and 69 cents a barrel, respectively, while the premiums for 90-octane gasoline stood at $2.65 and $4.83.

Their premiums for 95-octane gasoline were $2.65 and $5.13.

The tender would be awarded later on Thursday, the source said.

Ceypetco last bought via tender 40,000 tonnes of gas oil at a premium of 24 cents a barrel over Singapore spot quotes on a cost-and-freight Colombo basis between May 16-17.