A majority of Rockefeller family members, whose forefather founded ExxonMobil, announced Wednesday a shareholder drive to require an independent chairman of the energy giant's board of directors.

The Rockefellers are seeking support for a shareholder resolution to require an independent chairman so that the company founded by John D. Rockefeller "can better maximize long-term shareholder value in a rapidly changing energy environment," a statement by two family members said.

ExxonMobil chief executive Rex Tillerson also currently serves as the chairman of the company's board.

The unusual public call from the Rockefellers, the oldest continuous shareholders in the leading US oil and gas company, came a day before Exxon Mobil Corporation is to report first-quarter earnings.

ExxonMobil had a 2007 profit of 40.6 billion dollars, the largest US corporate annual profit in history, amid surging crude oil prices.

Peter O'Neill, head of the Rockefeller family committee dealing with ExxonMobil, and great-great-grandson of company founder John D. Rockefeller, is a filer of the shareholder resolution for an independent chairman.

The resolution received 40 percent support in 2007, at a time when ExxonMobil was announcing record-breaking earnings, the statement said.

"It was not an easy decision for the majority of the Rockefeller family to go public with our concerns. In fact, we have worked behind the scenes for a number of years now with ExxonMobil to avoid having to do so," O'Neill said.

Rockefeller family members have filed or co-filed four shareholder resolutions urging ExxonMobil to look beyond its current focus on oil and gas to "more effectively" address a rapidly evolving energy industry, particularly renewables and alternative fuels.

Competitors Shell, Chevron, BP, Total and Petrobras are expanding into renewables and alternative fuels to a much greater extent than ExxonMobil, the statement noted.

"Having an independent chairman leading an independent-thinking board of very experienced directors will substantially improve Exxon's ability to look the future squarely in the face and will increase its flexibility," O'Neill said.

Neva Rockefeller Goodwin, an economist and great-granddaughter of John D. Rockefeller, said: "ExxonMobil is profiting in the short term from investments and decisions made many years ago, and by focusing on a narrow path that ignores the rapidly shifting energy landscape around the world, including developing nations."

In addition, the Rockefellers warned that reliance on hydrocarbons will produce an "unrelenting" increase in global carbon-dioxide emissions blamed for global warming, with "devastating consequences, especially for those who are poor in resources and influence, whether they live in developed or developing countries."

Goodwin and O'Neill said that, after identifying a number of areas of vulnerability for ExxonMobil, Rockefeller family members met several times with the top management of ExxonMobil since 2003 to express their concerns.

Efforts to meet with the board and its key independent members have been declined, they said.