U.S. oil field services company Halliburton is mulling a counterbid for Britain's Expro International, sources close to the situation said on Friday.
Expro said on Thursday it had agreed a 1.605 billion pounds ($3.17 billion) bid from funds managed by private equity firm Candover and investment bank Goldman Sachs .
However, the oil services company added in its statement that another party, which had been given access to its books, continued to conduct due diligence.
Halliburton was not available for comment.
A spokesman for Expro declined to comment on whether the remaining party doing due diligence was Halliburton.
Expro accepted Candover's bid without giving other parties a deadline by which to submit bids, the normal practice in company auctions, the spokesman said.
Expro shares traded up 4.5 percent at 1,510 pence, ahead of Candover and Goldman's bid of 1,435 pence per share.