UPDATE 1-Clean Energy raises stock sale size, prices at discount

* Raises offering by 2.2 mln shares

* Offering priced at $8.30/shr

* Offer price at 8 pct discount to Thursday's close

* Shares fall 3 pct in pre-market trade

June 26 (Reuters) - Clean Energy Fuels (CLNE.O) said its public offering of 8.2 million shares was priced at $8.30 apiece, a discount of 8 percent to the stock's Thursday closing price.

The natural gas provider, one of the many energy firms who have chosen equity offerings as a means to raise funds to bolster their capital budget and expansion plans, had earlier said it plans to offer up to 6 million shares.

The underwriters, led by Merrill Lynch & Co, also have an option to purchase up to about 1.2 million additional shares to cover overallotments, if any.

The offering is expected to close on July 1.

Shares of the Seal Beach, California-based company fell 3 percent to $8.74 in trading before the bell on Friday. They closed at $9.00 Thursday on Nasdaq. (Reporting by Antonita Madonna Devotta in Bangalore; Editing by Anne Pallivathuckal)