Assets: Owns 22% of Metro AG, 7% of Metro Group and vast landholdings throughout Europe and North America.

FORBES: Europe

The main competitor for Karstadt is Kaufhof, a division of the huge Metro AG which has ample financial resources.

FORBES: Karstadt -- Lack of Money, Excitement and Growth Equals a Slow Death

Metro AG itself won't comment other than to say that these are "market rumors, " which doesn't exactly calm any frayed nerves over in Redmond.

ENGADGET: Microsoft downplays Metro design name, might face a lawsuit over all that street lingo

Except that during the summer months, Metro was dropped as a title (just after rumors that German wholesaler Metro AG had been in touch over the trademark).

FORBES: Microsoft Missed The Open Goal To Rebrand Windows With Metro

Metro AG, one of Europe's largest retailers, bought 7% of RSL and is marketing RSL's prepaid calling cards to the 122 million customers who shop in its stores.

FORBES: Srpska calling

Germany's Metro AG, one of Europe's largest retailers, bought 7% of RSL and is marketing RSL's prepaid calling cards to the 122 million customers who shop in its stores.

FORBES: Srpska calling

See Deborah Orr's roundup of Metro AG's foreign expansion in this issue: Even where a multinational company is willing to open up, its local partners (in skittish places like China) may not be.

FORBES: Retrograde Region

Both Ars Technica and The Verge hear from unverified sources that German retailer Metro AG might waving its legal guns and forcing Microsoft to quiet down over a potential (if questionable) trademark dispute.

ENGADGET: Microsoft downplays Metro design name, might face a lawsuit over all that street lingo