Shell suffered an embarrassing 10% shareholder rebellion against its executive pay report on Tuesday.

Almost 8% of the investor base voted against the company's remuneration policy, which handed its outgoing chief executive Peter Voser a €3.3m (£2.8m) cash bonus in a year when profits dropped by $1.6bn (£1.05bn) to $27bn.

A further 2% of investors abstained from the vote at Shell's annual meeting in The Hague.

The bonus took Voser's total salary package to €5.1m, down from €5.2m the previous year, although this is still more than double the $2.7m package given to BP boss Bob Dudley last year. Dudley received no bonus as the company continues to deal with the consequences of the Gulf of Mexico oil spill.

At the meeting, Voser refused to comment on the European commission investigation into claims oil companies have been rigging the price of oil and petrol for more than a decade.

Voser, who announced plans to stand down as chief executive earlier this month after less than four years in the job, said it would be "inappropriate to speculate about the outcome" of the European-wide investigation.

But he said Shell is committed "to achieve the highest standard of corporate behaviour".

Shell's offices in London and the Netherlands were subjected to dawn raids by European commission regulators investigating allegations big oil companies have "colluded" to manipulate oil and petrol prices since 2002.

The offices of BP, Norwegian oil company Statoil and oil price reporting agency Platts were also raided last week. The European commission has also written to oil traders and other players in the industry to explain how the $3.4tn global crude market works.

Shell's investors voted down its remuneration report in 2009, under which it planned to pay bonuses to its board even through it did not hit pre-set targets.