By Herbert Lash

NEW YORK (Reuters) - Concerns about economic growth and corporate profits pushed global shares lower on Thursday, overshadowing optimism among investors that interest rates will stay unchanged, a view that helped government debt rally.

The euro slid to a new seven week-low against the dollar after the European Central Bank left interest rates unchanged, as expected. The dollar index rose to a 5-1/2-month high after a surprise rise in the U.S. pending home sales index for June.

ECB President Jean-Claude Trichet said risks to economic growth were starting to materialize, leading investors to rule out more euro zone rate rises this year and the euro to weaken.

A similar view on the other side of the Atlantic took hold, spurred by a jump in U.S. jobless claims. The Federal Reserve -- the U.S. central bank -- is seen as unlikely to raise benchmark interest rates while unemployment is rising.

Renewed signs of shaky economies revived investors' appetite for safe-haven government bonds, sparking a rally in U.S. Treasuries and euro zone government debt.

A slew of major banks in Europe reported lower profits, took more write-downs on risky assets and braced for tough times well into 2009. Difficult conditions will persist but a few banks were also optimistic that opportunities would arise from the turmoil, helping send some bank shares higher.

In the United States, a big loss at insurer American International Group (AIG.N: Quote, Profile, Research) rattled investors and Wal-Mart Stores Inc (WMT.N: Quote, Profile, Research) missed July sales forecasts, heightening concerns about consumer spending and the profit outlook.

A government report showing the number of Americans in the latest week who filed for jobless benefits jumped to the highest in more than six years also unnerved investors.