"The deal, to be unveiled after 'the close of business' in New York on Tuesday," the Financial Times reported on Tuesday.
The deal would be RIL's second purchase of a US shale gas interest in as many months.
Separately, sources close to the matter had told PTI that Mukesh Ambani-led RIL is close to buying up to 40 per cent stake in shale gas assets.
Pioneer has about 3,10,000 acres in the Eagle Ford Shale play in South Texas, the US, and RIL is in talks to buy up to 40 per cent interest in them.
The company had made its first breakthrough in the US in April when it had acquired 40 per cent stake in Atlas Energy Inc's 3,00,000 acres shale gas property for $1.7 billion. Atlas' Marcellus shale gas project spans parts of West Virginia, Pennsylvania and New York.
Flush with revenues from its KG-D6 Gas field back home, the Mukesh Ambani-run petrochemical giant has been on the lookout of acquisitions in the US.
However, RIL and Pioneer did not commented on reports, the FT said.
Image: RIL chief Mukesh Ambani
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