Online travel company Expedia Inc. will buy Amgen Inc.’s offices in Seattle for $229 million, the company announced Thursday. Expedia, which currently has offices in the Seattle suburb of Bellevue, will move into the Amgen property by 2018. The waterfront campus consists of 40 acres, with 750,000 square feet of available office space and land for future expansion. The site also has restaurants and a fitness facility. In October, Amgen announced it would lay off 274 workers in Seattle and planned to exit Washington State by the end of 2015. At the time, the company operated a small manufacturing plant in Bothell outside of Seattle and had a total payroll in the region of 660 workers. The remainder of the workers will be laid off through the course of this year. The Washington State layoffs are part of a larger restructuring at Amgen. The company plans to reduce its payroll by as much as 2,900 workers, or 15 percent of its workforce. Real estate consolidation is another part of the restructuring; the company announced it will shut down its Onyx Pharmaceuticals subsidiary in South San Francisco and vacate the company’s building, with some of the workers moving to Amgen’s headquarters campus in Thousand Oaks. Expedia owns a number of popular travel sites, including Hotwire.com, Hotels.com and its namesake Expedia.com. In January it announced it will purchase competitor Travelocity.com for $280 million. The purchase of the Amgen property is expected to close in the second quarter.