By Rob Broomby BBC correspondent in Berlin

The American intelligence agency, the CIA, could have prevented the 11 September attacks if it were not for systematic failures, according to the German newspaper Die Zeit.

Just a month before the deadly attacks, the paper said, Mossad handed over to the Americans a detailed report naming several suspects they believe were preparing an attack on the United States

The paper has uncovered details of a major Israeli spy ring involving some a 120 agents for the intelligence service Mossad operating across America and some masquerading as arts students.

The ring was reportedly hard on the heels of at least four members of the hijack gang, including its leader Mohammed Atta.

But the Israeli agents were detected by their American counterparts and thrown out of the country, it says.

The US authorities said then that they were students whose visas had expired.

Report dismissed

Just a month before the deadly attacks, the paper said, Mossad handed over to the Americans a detailed report naming several suspects they believe were preparing an attack on the United States.

But it contained no specific indications as to the objective and it was not treated seriously.

The paper also claims that the CIA failed to inform the German authorities that Ramzi Binalshibh, a key logistics man for the attacks, had attended a high level meeting of al-Qaeda activists in Malaysia over 18 months before 11 September.

Without that information the Germans could not prevent him re-entering the country and contacting the Hamburg cell that was planning the hijackings.