Two rival bidders are preparing for the start of a last-ditch bidding war for Anglo-Dutch steelmaker Corus.
A bid from Tata kicked off the battle for Corus in October
India's Tata Steel and Brazil's CSN have until 30 January to make a final offer, otherwise the UK Takeover Panel will step in and begin an auction.
CSN has reportedly secured additional funding in case it decides to up its £4.9bn ($9.7bn) bid, while Tata is said to be prepared to offer 550p a share.
A merger will create the world's fifth biggest steel firm whichever firm wins.
Last month, Corus backed a 515p a share offer from Brazil's Companhia Siderurgica Nacional. That trumped an earlier offer of 500p a share from Tata.
Media speculation now suggests Tata could make a fresh approach of 550p a share, which would value Corus at £5.2bn.
Shares in Corus surged to seven year highs on Friday, before closing at 545p, amid reports Tata was preparing to raise its offer. Tata later denied the claims.
The Indian firm has warned it does not intend to overpay for Corus, but experts have said that if it had decided to drop its offer it would have done so by now.
Last month, watchdogs warned that if a competitive situation still remained in the run-up to 30 January it would step in with an auction process.
Such a move could result in the Takeover Panel asking for an increase of as much as 50p per share.
Surging metals prices and rising demand has led to a wave of consolidation in the steel industry.
Last year, Dutch-based Mittal merged with Luxembourg-based Arcelor in a 25.8bn euro (£17.7bn; $32.3bn) deal creating the largest steel-maker in the world.
Meanwhile, last week Germany's ThyssenKrupp said first quarter profits more than doubled to £656m amid strong demand for stainless steel.