The Dow Jones Industrial Average closed 97 points higher at 9,054 points in low-volume trade, the first time it had closed above 9,000 since 9 July.

The technology-heavy Nasdaq index rose 13.69 points to 1,422.94, its highest close since 5 July.

Thursday's gains reflect a rising hope that the recent rally may be sustained and that investors have finally managed to put the wave of corporate scandals behind them.

The rally was in part prompted by an analyst forecast that Microsoft's sales would pick up.

Salomon Smith Barney raised the software giant's rating, quoting a survey of technology buyers, who planned to buy more Microsoft products. Microsoft's shares rose 95 cents to $53.23.

"I do think that this firmness, even though it is on light volume, is a sign that the bottom is in," Susan L.Malley, chief investment officer for Malley Associates Capital Management, said.

Doubters remain

Some scepticism remains.

"The rally over the last month was an oversold bounce. The oversold condition was caused by the accounting scandals and the questionable ethics of some board directors or CEOs, but it has already been priced in," Craig Cummins, a trader at Cantor Fitzgerald said.

He added: "Is this the beginning of the next 3,000 point move up on the Dow? No, I don't see it that way."

Signs of recovery were indeed mixed. Telecoms equipment maker Ciena saw its shares fall 8% as it warned that the worst was still to come. It reported a quarterly loss.

The world's largest bookseller, Barnes & Noble, also posted weaker-than-expected earnings. Its shares fell 50 cents to $22.93.