Al Gore joins a California venture capital firm Kleiner Perkins Caufield & Byers as partner

Venture capitalists said the move could also help companies financed by Kleiner to establish ties with big business and government, and obtain subsidies that encourage use of new technologies. Gore''s part-time duties at the firm include investigating the growth potential of start-up companies focused on the alternative energy sector, and determining whether Kleiner Perkins should finance those companies.

The former vice president (VP) said he would donate his salary from the venture to the Alliance for Climate Protection, a non-profit policy foundation. Venture capitalists usually get a management fee of 2 per cent of the amount of money they invest.

But their main motivation is the potential for huge returns that comes from their 20 per cent share of the profit, when their start-ups go public or are acquired. Kleiner Perkins, one of Silicon Valley''s largest VC firms, did not say whether Gore would receive a management fee or participate in profit sharing.

Gore already sits on the board of Apple, and has an advisory role in Google. He is co-founder and chairman of Current TV, a San Francisco television network that broadcasts viewer-created content. He keeps an apartment in San Francisco and spends five to six days a month in the area.

Kleiner Perkins feels Gore will help the firm attract innovative start-ups, an advantage in the firm''s competition with other VC companies. Silicon Valley''s venture firms have focused increasingly on financing alternative energy start-ups, so-called clean-tech companies.

These early investors are risking billions of dollars on the proposition that solar power, ethanol, and other clean and renewable energy innovations will become major business opportunities as oil prices rise and federal and state government increase incentives for using alternatives to oil.