Vodafone late on Monday submitted a proposal to the European Commission designed to win authorisation for plans to acquire Mannesmann, Michael Tscherny, the Commission spokesman for competition, confirmed yesterday.
The Commission is currently reviewing the proposal, Tscherny said, refusing to provide further details.
Such proposals, called "undertakings" in Commission legal parlance, are submitted when the concerned companies recognise that the merger or acquisition could create or reinforce a dominant position.
For this reason, the Vodafone undertakings are widely expected to include divestment of Orange, the UK's third largest mobile operator, while Vodafone operates the largest in the British market.
"A major competition aspect was always going to be Orange," said Vodafone corporate communications director Mike Caldwell. "It's fair to assume that the future of Orange will figure highly" in the document the company had submitted, he said.
The Commission now has until February 28 to deliver its initial ruling on the compatibility of the acquisition with European antitrust rules.
If the Commission identifies "serious doubts" about the compatibility, it has another four months in which to carry out an in-depth investigation into the merger and its competition consequences.
Vodafone and Mannesmann agreed last week to a 180 billion euro ($A280 billion) merger, which will create the world's biggest telecommunications firm.