Upscale department store retailer Neiman Marcus Group is expanding its international reach with the purchase of the mytheresa.com global online luxury business.

The acquisition from founders Christoph and Susanne Botschen and Acton Capital Partners includes the Theresa flagship luxury fashion store in Munich, Germany.

The deal is expected to close later this year, although details of the purchase price haven't been disclosed. The business, which was founded in 2006, generates annual revenues of around $130m and ships to over 120 countries globally.

"With the acquisition of mytheresa.com, Neiman Marcus Group takes yet another strategically significant step towards our long range international strategy to more broadly serve the affluent customer around the world," says Karen Katz, president and CEO Neiman Marcus Group.

The mytheresa.com online store and Theresa boutique will be run as an independent subsidiary of NMG based in Munich. The company's management team including managing directors Dr Thomas Mueller and Jens Riewenherm and buying director Justin O'Shea will be continuing in their current roles.

An advisory board will be established for the independent business unit with Christoph and Susanne Botschen as well as representatives from NMG. The independent business unit will report to Joshua Schulman, currently president of Bergdorf Goodman. Schulman will add president of NMG International to his current responsibilities.