Handset vendor Sony Ericsson Mobile Communications is suing Clearwire, claiming that the U.S. WiMax operator copied its logo. The Sweden-based company and its U.S. counterpart filed suit on Friday in the U.S. District Court for the Eastern District of Virginia, seeking Clearwire's profits along with damages and an order to stop the use of Clearwire's current logo.

Both companies use round, green logos with swirling white or silver shapes inside. Sony Ericsson, formed as a joint venture between Sony and Ericsson in 2001, told the court it filed for a trademark on a version of its current logo as early as 2006 and has registered several iterations of the image with the U.S. Patent and Trademark Office. Clearwire was formed in 2008 as a joint venture among Sprint Nextel, the former Clearwire wireless broadband carrier and other partners.

"Prior to Defendants' use of their infringing sphere with swirl logos, Sony Ericsson was the only company in the mobile communications business that used a sphere with swirl logo in green and silver/white colors to identify its goods and services," .

Clearwire has already used a series of different swirling green marks on its WiMax desktop modems, laptop dongles and portable access points. But Sony Ericsson says it is most worried about Clearwire's plans to offer a branded handset. Clearwire has yet to put its own brand on a phone but has said it intends to. Late last year, .

When a Clearwire handset finally goes on sale, that will put Clearwire directly in competition with Sony Ericsson, which says it has sold almost 32 million phones in the U.S. Both companies sell their products both online and in brick-and-mortar retailers, including stores in the Radio Shack and Best Buy chains.