Clean Energy Fuels Inc., the Seal Beach company backed by T. Boone Pickens, started trading Friday after cutting the number of shares offered and their price.

The company, which provides natural gas for buses, taxis and other fleets, priced its shares at $12, below an earlier expected range of $13 to $17.

The shares rose marginally in trading Friday.

Clean Energy sold 10 million shares, raising $120 million. It earlier hoped to raise as much as $345 million by selling 20 million shares.

The company's market value is estimated at about $600 million.

Legendary oilman and corporate raider Pickens is Clean Energy’s principal shareholder, founder and a director. He owns about 73% of the company.

He started Clean Energy as a tiny part of Dallas-based Mesa Petroleum in the late 1980s. He split it off in the late 1990s.

Clean Energy’s day-to-day operations are run by chief executive and cofounder Andrew Littlefair.

Pickens has invested about $50 million in the company in recent years and has extended it a $100 million line of credit.

In December, he cancelled about $70 million in debt owed to him and assumed liabilities worth $79 million in exchange for the right to buy up to 15 million shares at $10 apiece.

Pickens and his wife had planned to sell about 6 million shares in the IPO.

Last year, Clean Energy had sales of $91 million and had an operating loss of nearly $9 million. It’s been profitable in prior years.

Clean Energy plans to use the proceeds of its offering to build a liquefied natural gas plant, add natural gas fueling stations, buy natural gas vehicles for sale to customers, as well as for general purposes.