UPDATE 1-Clean Energy to offer up to 6 mln shares

June 22 (Reuters) - Clean Energy Fuels (CLNE.O) said it plans to publicly offer up to six million shares of its common stock and use the proceeds for working capital and other general corporate purposes.

The natural gas provider said it has not determined the price of the offering.

Clean Energy said it expects to grant the underwriters, led by Merrill Lynch & Co, a 30-day option to purchase up to an additional 900,000 shares of its common stock.

The company also said the proceeds may be used to fund capital expenditure related to station construction activities, investment in its LNG and biomethane plant or future acquisitions of natural gas fueling infrastructure, vehicle or services businesses and biomethane production assets.

Energy firms in the U.S. are cashing in on a recovery in broader markets by offering additional shares aimed mainly at boosting capital expenditure and enhancing their expansion plans.

Last week, fuel-cell power plants manufacturer FuelCell Energy Inc (FCEL.O) and oil and gas explorer McMoRan Exploration Co (MMR.N) also announced public offerings.

Shares of the Clean Energy closed at $8.86 Friday on Nasdaq. (Reporting by Antonita Madonna Devotta in Bangalore, Editing by Dinesh Nair)