The holders, who include several blue-chip European and US institutional investors, claim they speak for at least 40 per cent of WPP's convertibles, and are threatening to vote down an improved offer made last week.
The dissidents say they have made it clear in the past few days that the terms are not sufficient. Renewed worries about the refinancing sent WPP's shares 8 per cent lower to 46p yesterday.
It is understood that the two sides are considering sweetening the proposals with a new equity instrument. Preference shareholders were asked to convert about two shares for one ordinary. Under a new offer they will receive one and half new ordinaries for every two preference.
A spokesman at Samuel Montagu, WPP's financial adviser, said: 'As far as the banks are concerned, the refinancing plans have been completed. It is now a matter of take-it-or-leave-it from shareholders' point of view.'
The company hopes to publish a formal circular on the current proposals this weekend.Reuse content