HOUSTON, May 1 (Reuters) - The U.S. Federal Trade Commission (FTC) could release its decision in the coming days on an anti-trust review of Exxon Mobil's $60 billion acquisition of Pioneer Natural Resources.

Exxon last week said it responded to the FTC's second request for information and received no indications of anti-trust issues. The agency has 30 days to make a decision following the response, which is expected to have started in early April.

Exxon Chief Executive Darren Woods on Friday said the company had supplied an enormous "material of documents, contracts, line items on productions and sales."

"We are very confident that there are no antitrust issues," he told analysts on an earnings call.

The FTC's 30-day review period likely began in early April, said Bob Brackett, an analyst with Bernstein investment firm. "Few obstacles remain to an imminent second-quarter close."

An Exxon spokesperson said on Wednesday, "We continue to work constructively with the FTC as they conduct a very thorough review."

The FTC has stepped up its review of oil and gas deals and sent a second request to both companies last year. The regulator has also sought additional information from Chevron, Diamondback Energy, Occidental Petroleum and Chesapeake Energy related to their respective acquisitions of rivals.

Antitrust experts said in October that despite the size of the proposed Exxon-Pioneer deal, the FTC would struggle to stop it because it is a merger of producers rather than refiners or retail outlets. (Reporting by Sourasis Bose in Bengaluru and Sabrina Valle in Houston; Editing by Shailesh Kuber and Josie Kao)