In another high-profile protest over executive pay, Royal Dutch Shell shareholders rejected the company's remuneration report at today's annual meeting by a 59.4 percent to a 40.6 percent margin.

At Shell, it appears that investors objected to the remuneration committee's decision to approve the vesting of long-term incentive plan awards despite the failure of the Anglo-Dutch oil company to meet pre-set performance targets.

Co-operative Asset Management and Standard Life Investments were among the institutional investors that publicly opposed Shell's pay practices, according to The Times of London. The Association of British Insurers issued an "amber top" alert to its members before the meeting, according to the Times.

"We are taking this very seriously and we will be meeting with shareholders to take the right decisions," Shell chairman Jorma Ollila said after the vote, according to news reports. "We have already introduced additional performance measures for future awards reflecting on comments from shareholders."

Shell is the fifth U.K.-listed company where remuneration reports have failed to win majority support this year. In recent weeks, pay reports at Amec, an engineering firm, and mortgage lender Provident Financial failed to earn majority support. Earlier this year, pay reports were rejected at the Royal Bank of Scotland and homebuilder Bellway. There also was significant dissent against remuneration reports at oil giant BP, mining firm Xstrata, and Rightmove, which publishes online real estate listings, the Times reported.