UPDATE 1-Microsoft loses US patent suit vs Alcatel-Lucent

(Adds Microsoft comment)

WASHINGTON, May 20 (Reuters) - Microsoft (MSFT.O) lost a lawsuit that had accused Alcatel-Lucent (ALUA.PA) of violating patents used in business telephone networks, the U.S. International Trade Commission said on Tuesday.

Microsoft had accused Alcatel-Lucent of infringing four patents for software in a system that integrates telephones with computers for calls, messages and videoconferences.

"The commission has determined that there is no violation of section 337," the ITC said in its ruling. Section 337 refers to infringing intellectual property.

The administrative law judge hearing the case, Paul Luckern, had initially ruled that Alcatel-Lucent infringed one of the four patents in the initial suit. The full commission said on Tuesday that Alcatel-Lucent did not infringe on the fourth patent either, both companies said.

"We are pleased with the ITC's decision and had always believed that we had a strong case," said Alcatel-Lucent spokeswoman Mary Ward.

Microsoft spokesman David Bowermaster said the software giant was disappointed.

"We are disappointed that the International Trade Commission reversed Judge Luckern's ruling that Alcatel-Lucent infringed Microsoft's '439 patent. We look forward to receiving the detailed ruling so we can understand the Commission's reasoning," Bowermaster said in an e-mailed statement. (Reporting by Diane Bartz; Editing by Christian Wiessner)