Department store chain Macy's will build a major new fulfillment near Martinsburg in Berkeley County, West Virginia, to support continued growth of its online business.

The site is located north-west of Washington, DC. Construction on the 1.3m-square-foot facility is expected to begin in spring 2011, with operations beginning in April 2012 and order shipments starting in summer 2012.

The fulfilment centre is expected to employ approximately 1,200 full- and part-time staff year-round.

During the holiday shopping season, around 700 temporary associates are expected to be employed each year, to manage a higher level of online orders from customers.

Macy's said in the first 10 months of this fiscal year its online sales were up 29% compared with last year.

"Our Internet sales continue to grow rapidly as part of the omnichannel strategy at Macy's and Bloomingdale's - allowing customers to shop seamlessly in stores, online and via mobile devices in a manner that meets their needs and preferences," said Terry J Lundgren, chairman, president and chief executive officer of Macy's.