The battle for control of the UK's biggest power station, Drax, took another twist yesterday with a bid from BHP Billiton.

The move by BHP, the world's largest diversified resources company with a market capitalisation of £26.2bn, led to the plant's owner, AES Drax Holdings, seeking extensions to the deadline on other offers.

The Anglo-Australian group is hoping its offer will beat those from International Power and investment bank Goldman Sachs.

Their offers were due to expire yesterday, which prompted AES to push for the deadline to be extended to Friday to consider its options.

Gordon Horsfield, chairman and director of AES Drax Holdings, said: "In order for the three offers to be properly considered, the directors are looking to extend the deadline for existing offers beyond Friday, August 22.

"Clearly, we are extending every effort to deal with all parties on a fair and constructive basis."

Goldman Sachs' interest will be purely financial, while International Power, which increased its original offer when it was outbid by the investment bank, will want to be involved in the day-to-day running of the station.

Billiton, on the other hand, is not offering the highest price but has attached potentially attractive coal supply deals to its bid.

The future of the power station, which is near Selby, in North Yorkshire, has been in doubt since its US owner, AES, abandoned restructuring plans for its £1.3bn debt earlier this month, after failing to reach an agreement with creditors.

The plant has been hit by a 40 per cent slump in wholesale electricity prices and was plunged into crisis last year when its biggest customer, electricity supplier TXU, was put into administration and failed to pay a £50m bill.

BHP is understood to be interested in the 3,960-megawatt power station because of the £250m of coal it buys every year.

A spokesman for the company said: "We have a long-term interest in the European energy market as we are one of the world's leading fuel suppliers."

BHP is expected to use coal it produces from its mines in South America and South Africa to fuel Drax if its wins control of the plant.

The company's bid is thought to include a 15-year coal supply deal for BHP.

The offer, of 70p in the pound for part of Drax's debt, is worth up to £95m and beats other bids.

International Power offered 65p in the pound while Goldman Sachs bid 64p. The former National Power unit was regarded as the front runner after revising its bid earlier this week.

BHP employs 38,000 staff worldwide - about 1,300 in the UK at Liverpool, London and offshore at Aberdeen.