FACEBOOK has announced plans to open a software engineering centre in New York in early 2012. The firm already employs an advertising team in the city. However, it is the first time the company has created a software base that is not on the US West Coast. Reports also suggest the social network has bought Gowalla - a location-based check-in service. The moves come ahead of an expected stock market flotation. Facebooks chief operating officer, Sheryl Sandberg, announced the New York expansion plan at a press conference attended by the citys Mayor, Michael Bloomberg, and other officials. We are trying to grow at a clip that will allow us to get the very best people and integrate them, she said. We will be adding thousands of employees in the next year. The new office will be headed up by Serkan Piantino. He previously led the engineering team behind Facebooks News Feed and helped develop its Timeline feature. Ms Sandberg did not specify how many of the thousands of promised posts would be created in New York. Reports suggest the firm has also taken over Gowalla. Texas-based Gowalla is a two-year-old social network based around the idea of allowing users to check-in to locations and share pictures from their visits. BBC