The company kickstarted the sale earlier this morning as it seeks to refinance the perpetual bonds it sold in 2013.

"The proceeds will be used to refinance the perpetual bond, call option for which is due in February 2018. We are expecting a tight pricing because this issue comes just a day after the sovereign upgrade," said a person aware of the deal.

RIL had raised $800 million in 2013 at 5.87 per cent with a call option in five years. A call option gives the seller of the bond a chance to buy it back.

The initial guidance for the new 10-year bond is 150 basis points above the 10-year US treasury which ended Friday at 2.34 per cent.

"We are hoping that the pricing will tighten as demand picks up through the day," said the person cited above.

Bankers are hoping to take advantage of credit rating agency Moody's India upgrade to second notch investment grade or Baa2 on Friday.

RIL is rated on par with the sovereign rating. Companies cannot be rated higher than their sovereign.

In a note after the sale was launched today Moody's said Baa2 rating reflects the company's strong cash flows.

"RILs Baa2 ratings reflects the company's strong ability to generate operating cash flows, with annual EBITDA exceeding $10 billion from its large scale integrated refining and petrochemical operations which generate strong margins and the company's nascent but growing digital serviced business," sqie Vikas Halan, senior credit officer at Moody's.