Oracle is suing Alcatel-Lucent, claiming the massive telecom is in violation of a number of Oracle's patents, according to documents filed with the U.S. District Court for the Northern District of California.

Alcatel-Lucent emphatically denies Oracle's claims and is charging in turn that some Oracle software -- including its flagship database -- infringes on some of Alcatel-Lucent's patents.

Oracle's patent-violation claims center on a number of Alcatel-Lucent products, including the OmniTouch messaging system and the 5350 XML Document Management Server, documents show.

Oracle first filed suit

on May 7.

The company is seeking unspecified monetary damages, as well as a declaratory judgment that it is not infringing on Alcatel-Lucent's intellectual property. Alcatel-Lucent's counterclaim calls for similar measures against Oracle.

Meanwhile, court documents state that in December 2007, Alcatel-Lucent sent a letter to Oracle CEO Larry Ellison alleging that Oracle's database and the product's Data Guard, TimesTen and Data Mining options were in violation of Alcatel-Lucent patents. Oracle's Email Center and Siebel CRM Call Center On Demand products are also in violation, Alcatel alleges.

A document that Oracle filed on Wednesday alleges that a number of the patents Alcatel-Lucent cites are invalid and unenforceable because individuals involved with the patent approval process withheld "information material to patentability" from the U.S. Patent Office "with the intent to deceive."

An Alcatel-Lucent spokeswoman said Thursday that the company would have no additional comment. An Oracle spokeswoman did not immediately respond to a request for comment.