Unbenownst to German intelligence in Berlin, the United States was in full control of one of Germany's most trusted spy rings during the crucial World War II years of 1944 and 1945.

From Jan. 7, 1944, to the end of the war with Germany in May 1945, according to once-secret documents just turned over to the National Archives by the Nationald Security Agency, the United States wrote 342 messages sent by German agents under American control in New York Baltimore and Washington to intelligence headquarters in Berlin.

The messages contained a mix of fact and fabrication deliberately designed to mislead the Germans about U.S. war plans. So convincing were the messages that the Germans passed many of them on verbatim to their Japanese counterparts in Tokyo.

In releasing the declassified messages, the NSA made no mention of how many German agents were under U.S. control in 1944 and 1945. It also did not say whether the German agents were in prison, under house arrest or merely under surveillance during the time they were used to relay the misleading messages to Berlin.

Under the code names Bluebird and Broadaxe, the Joint Security Control Section of the U.S. Joint Chiefs of Staff radioed coded messages to Hamburg under the real names of German agents detailing American war plans, production figures and troop movements. The controlled German agents' "handlers" in Hamburg then passed them on to Berlin.

Often, the messages complained about late payment for services to give them a flavor of reality. Messages also worried about they way the War was going against Germany. Said one message from Washington: "I am preoccupied with my security in case of the sudden end of the war. What am I to do? Do you wnat me to continue to send reports?"

Mostly, the messages were intended to mislead the Germans by concealing fabrications behind a veil of unimportant fact. Many messages were constructed to give the Germans and Japanese the impression that the United States was even stronger than it was.

The messages to Berlin said the United States was producing a weapon like the German V 1 rocket, which in fact it was not. Other messages implied that the United States was testing at least three jet fighters in 1944, when in fact it was not. On several occasions, reports were sent to Germany hinting at an American invasion of China, knowing this misleading information would be passed on the the Japanese.

One message pointed out that stories of atrocities against American prisoners of war only stirred public opinion against the Germans and Japanese. This message said that atrocity stories resulted in wounded American soldiers staying in the Army to fight rather than accepting disability discharges.

Totally misleading were exaggerated stories of U.S. might, of "robot bombs" that flew unguided to their target, of 40,000-pound bombs that devastated cities and of 600 mile-anhour jet fighters soon to be deployed in Europe and the Pacific.

Only once was development of the atomic bomb mentioned, in an apparent attempt to see how the Germans would react. Said a Nov. 14, 1944, message from Baltimore to Hamburg: "A short time ago, I read a newspaper report that factories on the West Coast are trying to manufacture bombs based on the principle of atom-smashing."