British Gas owner Centrica is to expand its retail presence in the US with the purchase of New York-based energy retailer Gateway Energy Services.The company is paying $90m in cash, including $13m of tax assets plus additional working capital, for Gateway.The New York-based company has more than 275,000 gas and electricity customer accounts, located mainly in New York State, New Jersey and Pennsylvania. The company will become part of Centrica's North American subsidiary, Direct Energy, and will increase the subsidiary's residential and small business customer relationships to more than 800,000 in the US Northeast."Competitive retail markets in the North Eastern United States provide us with opportunities to grow our North American business. Gateway builds on the progress we've made in North America over the past decade and represents another important step towards our stated goal of doubling the profitability of Direct Energy," said Direct Energy President and chief executive officer, Chris Weston.