Hostage issue underscores German role in Gulf conflict. RELEASE IN LEBANON

The release of West German hostage Rudolf Cordes in Lebanon would underscore the complex diplomatic maneuvers required by Western governments in the age of international terrorism. There were conflicting claims Monday about the status of Mr. Cordes, a chemical company manager held for nearly 20 months. One report claimed he had been released while a statement apparently from the kidnappers said he would be freed only if representatives of West Germany, Iran, and Syria were present for his release at a hotel in Moslem west Beirut. A letter apparently written by Cordes was sent to the Beirut newspaper an-Nahar at dawn on Monday - saying he was about to be freed.

As of press time, West German officials could not confirm his release. Foreign Ministry officials did say, however, that they were expecting the release within 48 hours.

``A month hasn't passed that we haven't tried to press for [his release],'' says a spokesman in Bonn, who confirmed that West German diplomats were standing by in Damascus and Beirut to aid in the transfer.

The focus of West Germany's diplomatic efforts has been Iran - which is thought to wield strong influence over the Beirut-based Shiite Muslim group which claimed responsibility for the kidnapping. West German Foreign Minister Hans-Dietrich Genscher met last week in Bonn with Iran's deputy foreign minister, Muhammad Javad Larijani, to discuss the issue. Diplomatic sources say that Mr. Genscher was assured during this meeting that Cordes's release was imminent.

Genscher also pressed the hostage issue during a meeting with Iranian Foreign Minister Ali Akbar Velayati on Aug. 20. The meeting occurred in Pakistan, where both men were attending the funeral for Pakistani President Mohammad Zia ul-Haq.

Iran has good reason to try to be helpful. West Germany - which trod a careful policy of neutrality in the Gulf war - is standing ready to take part in Tehran's post-war reconstruction effort. The West Germans have long played a key role in supplying technological know-how to both Iran and Iraq.

Still, the release comes at a sensitive time. The trial of accused hijacker Muhammad Ali Hamadei resumed in Frankfurt last week.

The case is closely linked to Mr. Cordes - who was grabbed by kidnappers just days after Mr. Hamadei was arrested in West Germany in January 1987. Western officials believe Cordes and another West German hostage (who has since been released) have been used to press for special treatment for Hamadei.