Kosmos Energy's stock tumbles after largest shareholders pare holdings

Shares of Kosmos Energy Ltd. tumbled 6.5% in premarket trade Tuesday, after the oil and gas exploration company said a large stock offering by its two largest shareholders priced at a discount. The company said late Monday that Blackstone Group , its second-largest shareholder, was selling 30 million shares to the public, and that Warburg Pincus, its largest shareholder, was selling 10 million shares. The secondary offering represents about 10.3% of the total shares outstanding. On Tuesday, Kosmos said the offering priced at $7.25 a share, or 7.5% below Monday's closing price of $7.84. The stock had run up 32% since May 5, after the company reported better-than-expected first-quarter results, to be up 12% year to date through Monday. In comparison, the SPDR Energy Select Sector ETF has lost 9.8% this year, while the S&P 500 has gained 6.9%.

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