LONDON (AFX) - The euro slumped below the 0.90 usd level after the release of weaker-than-expected German Ifo business sentiment numbers, dealers said. Just before the release at 9.00 am, the euro was trading at 0.9015 usd. By 9.02 am, the euro had fallen down to 0.8985 usd. The West German Ifo business climate index fell to 85.0 in September from 89.5 in August, and was down from 98.2 in September last year. The AFX consensus of economists had forecast a fall to 88.4 in September. The September business assessment index was 79.6 down from a revised 83.2 in August. Last month, Ifo said the August business assessment index was 83.3. The West German business expectations index was 90.6, down from 95.9 in August, and down from 103.0 in September 2000, Ifo said. The euro has struggled all week, unable to capitalise on the multitude of difficulties afflicting the dollar, from poor economic news to the anthrax alert which forced the closure of Capitol Hill on Wednesday.