Hutchison Whampoa is understood to have been the key to Vodafone AirTouch's successful 175 billion euros (about HK$1.33 trillion) takeover of Mannesmann, the German telecommunications and engineering group, in which Hutchison holds a 10.1 per cent stake.
As a result of the deal, Hutchison has seen the value of its holding in Mannesmann rise by almost 2.5 times in just three months.
Banking sources close to the bid battle believe Hutchison is also set to become the merged group's largest single shareholder with a 5.05 per cent stake, if as expected, it accepts the Vodafone offer.
Hutchison was bound by a contractual obligation not to accept any bid for Mannesmann unless it had first received the recommendation of the Mannesmann board.
However, bankers claim Hutchison put pressure on the Mannesmann board to accept the bid.
'You would expect Mannesmann's largest shareholder to have a say in what happens,' a banker close to Vodafone said.