By Andrea Shalal

COLOGNE, Germany (Reuters) - Germany and the Netherlands will in October test joint operations of their Patriot air and missile defense systems in what could be a model for multilateral deployments to Poland or the Baltic states in coming years, a top German general said.

Brigadier General Michael Gschossmann said joint operations enabled by the new approach could help NATO reassure Baltic member states and Poland, which are clamoring for more defense after Russia's annexation of Ukraine's Crimea region.

Latvia, Lithuania and Estonia say they fear Russian aggression should Moscow's relations with the U.S.-led Atlantic alliance deteriorate further. The Baltic states are linked to the rest of NATO only by a narrow strip of land running between Belarus, a staunch ally of Russia, and Kaliningrad, the heavily militarised Russian coastal enclave.

The October test will validate a new joint concept of operations for air and missile defense developed by Germany and the Netherlands over the past year, the first of its kind in Europe, Gschossmann, commander of ground-based units for Germany's Air Force, told Reuters in an interview.

More than 40 interceptors will be fired during an exercise at a NATO site in Crete in early October that will include 300 German and 100 Dutch soldiers, as well as 10 U.S. soldiers and a U.S. Aegis destroyer, according to German and U.S. officials.

After the test, German and Dutch military officials plan to declare their Bi-national Air & Missile Defence Task Force ready for combat, and will offer it to NATO for future deployments.

Baltic state officials welcomed U.S. deployment of a Patriot battery to eastern Europe during a series of exercises earlier this summer, but the symbolic value would be greater if the deployment involved more than one country, Gschossmann said.

"REASSURANCE"

"We could offer even more reassurance and send a political signal if we took a mixed task force with German, Dutch and U.S. Patriot systems - a purely defensive asset - and set it somewhere in Poland or the Baltic states."

Dutch, German and U.S. Patriot missile systems were rolled out separately in Turkey for two years from January 2013, where they helped protect fellow alliance member Ankara's air space against the possibility of missile attacks from war-torn Syria.

The new German-Dutch concept of operations uses the Surface to Air Missile Operations Centre, which was initially developed by Airbus Group SE for the German Air Force.

The SAMOC system can now manage all air defense equipment operated by NATO members, although Soviet-style surface-to-air missile systems still used by Poland and other eastern European states as a legacy of their Communist past cannot be fully automated and requires a human in the loop.

The German-Dutch air and missile defense cooperation, signed in January and known as Project APOLLO, is part of a broader series of steps that have closely bound the two countries' navies and ground forces together in recent years.

Gschossman said Germany and the Netherlands also plan to jointly develop an air defense system operated directly by their armies to replace the Stinger guided missile, which must be phased out in the next decade.

Dutch Defence Ministry spokesman Jeroen de Vries said the two countries were looking into integrating the Dutch and German Patriot missile systems. "The task force can be deployed within NATO as capacity to protect alliance territory," he said.

(Additional reporting by Thomas Escritt; editing by Mark Heinrich)