Emulex (Costa Mesa, Calif.) also alleged in its suit that Broadcom has made defamatory statements and engaged in acts of unfair competition in violation of seven separate statutes.

The antitrust claims seek unspecified damages, plus attorneys' fees and costs and injunctive relief, Emulex said. The complaint also seeks punitive damages against Broadcom for "malicious" conduct, Emulex said.

Broadcom (Irvine, Calif.) in September sued Emulex, claiming that the company infringes on 10 Broadcom patents related to networking and communications technologies.

Earlier this year, Broadcom tried for several months to acquire Emulex, including the initiation of a tender offer that was eventually worth $11 per share. Emulex' board of directors repeatedly rejected Broadcom's overtures and advised shareholders not to accept the tender offer, saying it undervalued the company.