NEW YORK (Bloomberg) Bermuda-based Kosmos Energy Ltd, the oil and natural-gas company owned by Warburg Pincus LLC and Blackstone Group LP, gained 1.3 percent in its first day of trading after raising $594 million in its initial public offering.The exploration and production company sold 33 million shares at $18 each, 10 percent more than it sought, according to a statement. Shares of the company, a partner in the Jubilee oil field off the coast of Ghana, rose 24 cents to $18.24 in New York Stock Exchange composite trading.“These guys have a very good track record,” said Fadel Gheit, an analyst at Oppenheimer & Co. in New York. “They are known and they are backed up by two very smart private-equity funds.”One of the advisers involved in the deal was Bermuda law firm Conyers.Marcello Ausenda, director in Conyers’ Bermuda office, said: “Our Cayman and Bermuda offices worked together to provide integrated advice that facilitated the exchange of units by the Cayman company stakeholders for shares in the Bermuda IPO company.“Kosmos’ decision to use Bermuda for the IPO company underscores Bermuda’s attractiveness for large public transactions of this kind. We were pleased to provide legal advice alongside Cayman in this innovative, and ultimately, very successful, transaction.”Warburg and Blackstone completed the Kosmos offering after crude oil futures traded in London reached a 32-month high last month. Kosmos has about a 23 percent stake in Ghana’s Jubilee oil field, the biggest offshore discovery in West Africa in a decade, according to the prospectus.Warburg and Blackstone may be capitalising on the climb in crude oil and a recent spate of private equity-backed IPOs. Crude futures gained 11 percent in the first quarter of this year in New York trading to average $94.60 a barrel, from the $85.24 average for the last three months of 2010.The 33 million shares represent a nine percent to 10 percent stake in the company, said Cathleen Mayrose, a Kosmos spokeswoman who works for CounterPoint Strategies Inc. in New York.Kosmos doesn’t intend to pay a dividend on its shares. Proceeds from the sale will fund exploration and drilling in Ghana and Cameroon through 2013. The company is also making a $15 million payment to Ghana National Petroleum Corp under a prior agreement to “resolve our past disputes”, according to its April 25 prospectus.The company has net proved reserves of 56 million barrels of oil equivalent, according to the prospectus. Based on the price per barrel of reserves, the share sale was expensive, Gheit said.