Sir John Bond, the new chairman of Vodafone, yesterday expressed support for Arun Sarin, but warned that the chief executive's performance would be under "constant review".

Mr Sarin suffered embarrassment when investors holding 15 per cent of Vodafone's shares either voted against his re-election as chief executive or abstained at the annual meeting.

It is believed to be the biggest ever protest against a Vodafone director. The company had further discomfort when investors holding 20.2 per cent of its shares voted against its remuneration policy or abstained.

Sir John said he "subscribed" to comments by Lord MacLaurin,Vodafone's outgoing chairman, who voiced strong support for Mr Sarin, but warned he had to deliver results on the company's new strategy for reviving its flagging performance.

Some of Vodafone's big investors that are critical of Mr Sarin are looking to Sir John to conduct a swift review of the board, and decide whether to replace the chief executive. Sir John, asked about his review, said: "Wherever you work in the world, the performance of management is under constant review."

Mr Sarin's re-election as chief executive was opposed by three of Vodafone's top 10 investors. They were Hermes Pension Management, Morley Fund Management and Standard Life Investments. Some big investors also abstained. Mr Sarin has come under increasing criticism from some investors after Vodafone warned last November of slowing revenue growth and reduced profit margins.

In May, it announced a record pretax loss of £14.9 billion (€21.8 billion).

Vodafone's remuneration policy was criticised at the meeting because the company plans to cut the earnings growth targets that management must hit for share option awards from 8-16 per cent in 2006 to 5-10 per cent for 2007.

Standard Life, which voted against Vodafone's remuneration policy, said its stance reflected "the importance we attach to leadership at Vodafone and our concerns about Vodafone's remuneration policies, which in our opinion provide significant rewards for achieving unchallenging performance conditions".

Lord MacLaurin described the protest on the remuneration policy as a "yellow card" against the company.

Vodafone's US partner Verizon Communications has signalled an interest in buying Vodafone's stake and some investors have urged Vodafone to sell and return the proceeds to shareholders. Vodafone shares closed up 0.4 per cent at 115-3/4 pence. Its shares have underperformed the DJ Stoxx European telecoms index by about 5 per cent this year.