The millennium will begin with the world's biggest takeover bid, as a battle royal for the control of Europe's mobile phone industry formally commences on Christmas eve.

Vodafone, the UK's largest company, is set to submit its £83bn bid ($134bn) for Mannesman on Thursday, with the takeover clock beginning to tick from Friday, Christmas Eve.

Vodafone chief Chris Gent is due to fly to Dusseldorf to present the 500 page plan to investors.

Under takeover rules Mannesmann has until 7 January to publish its defence, and shareholders will have to decide on the offer by 7 February.

Vodafone says it is not increasing the amount on the table, and has decided not to wait for clearance from the European regulatory authorities.

Regret not friendly

Executives from Vodafone and Mannesmann have spent much of the month competing for the loyalties of shareholders in the German conglomerate.

Although Mannesmann chairman Klaus Esser has not ruled out an amicable settlement, he insists that Vodafone's offer is far less than Mannesmann's potential value.

If successful under current terms, Vodafone's bid would be the biggest takeover bid in history, topping MCI WorldCom Inc.'s $115bn bid for Sprint Corp.

Mannesmann said it "extremely regrets" that Vodafone insists on pursuing the company with a hostile takeover bid.

"At no time has Vodafone made a friendly approach with an offer acceptable to Mannesmann shareholders," it said.

"Mannesmann would contribute more than half of the growth to a combined business. An offer of 47.2% of the combined business for Mannesmann shareholders is completely inadequate," the company said.

The European Commission announced on Tuesday it had no objection to Mannesmann's purchase of Orange.

Meanwhile, some Mannesmann shareholders say they are launching a court action in the United States to try and force the company to talk to Vodafone.