The independent U.S. oil and gas exploration and production company could announce a deal, valued at just over $2 billion, with the Thai energy company as early as Thursday, said one source, who declined to be identified as the news is not public.

Reuters reported in November, citing sources, that Murphy Oil was in talks to sell the assets after an unsolicited bid that could fetch between $2 billion to $3 billion.

Murphy, which has been in Malaysia for two decades, could not be reached outside regular U.S. business hours. There was no immediate response from PTTEP to a Reuters query.

Murphy had tapped banks for the potential sale of its majority interests in eight separate offshore production sharing contracts in Malaysia, sources had said.

Others familiar with the matter had suggested Spanish oil major Repsol, whose presence in Malaysia is focused on its upstream business, or other global majors could be potential buyers for Murphy's assets.

The potential transaction between Murphy and PTTEP comes as M&A activity is heating up in Malaysia's oil and gas sector, where international companies pursuing expansion plans are spotting opportunities. In September, Austrian oil and gas company OMV agreed on a joint venture with Sapura Energy Bhd, paying $540 million for a 50 percent stake in the exploration assets of the Malaysian firm.

In August, citing sources, Reuters reported that U.S. company Hess Corp's Southeast Asian offshore natural gas assets had attracted bid interest from PTTEP and OMV. Hess later said it had no plans to sell its Southeast Asian assets. Malaysian state-owned Petronas partners Murphy in Malaysia.

People familiar with Murphy's business had said the company could use the sale proceeds to fund its global expansion plans.

In September 2014, Murphy announced the sale of a 30 percent stake in its Malaysian assets to Indonesian state oil company Pertamina for $2 billion as it cut its overseas holdings.

(Reporting by Kane Wu in HONG KONG and Anshuman Daga in SINGAPORE; Additional reporting by Chayut Setboonsarng in BANGKOK; Editing by Sumeet Chatterjee and Tom Hogue)

By Kane Wu and Anshuman Daga