By Samuel Howard

Law360, New York (May 11, 2010, 2:45 PM ET) -- Intervening in U.S. Ethernet Innovations LLC’s sweeping infringement action, Intel Corp. and Marvell Semiconductor Inc. allege that the networking patents broadly asserted against computer manufacturers they supply — including Apple Inc., Dell Inc. and Toshiba Corp. — are invalid.

Marvell and Intel filed separate intervenor complaints Monday in the U.S. District Court for the Eastern District of Texas, seeking declaratory judgment that the networking products they provide the targeted computer companies do not infringe the four USEI patents-in-suit.

The intervenors maintain that the desktop adapters and...