* Shares open at $19.50
* 17.5 million shares were sold at $20.50 each in IPO
* Shares trading on NYSE under symbol "NKA"
NEW YORK, May 12 (Reuters) - Niska Gas Storage Partners LLC (NKA.N) shares opened 4.9 percent below their initial public offering price on Wednesday.
The shares opened at $19.50, fell as low as $19.20, then recovered to $19.73 in early trading on the New York Stock Exchange.
Niska on Tuesday sold 17.5 million shares at $20.50 each, raising $358.75 million. It had planned to sell 17.5 million shares at $20 to $22 each after raising the expected price range from $19 to $21 in April.
Niska is the largest independent owner and operator of natural gas storage and assets in North America and owns facilities in Alberta, Canada, northern California and Oklahoma, according to a regulatory filing.
Funds affiliated with private equity firms Carlyle Group [CYL.UL] and Riverstone Holdings will control Niska's business operations after the IPO, according to a filing with the U.S. Securities and Exchange Commission.
Niska said it would use proceeds from the IPO to repay revolving credit and for general purposes.
Goldman Sachs & Co and Morgan Stanley led 11 underwriters on the offering. (Reporting by Clare Baldwin; editing by John Wallace)