Microsoft on Thursday said its profit dipped slightly from a year earlier but posted record revenues in the past quarter, getting a lift from sales of its new Windows 8 operating system.

Profit dipped 3.7 percent from 12 months ago to $6.38 billion, better than most forecasts, while revenues rose 2.7 percent to $21.46 billion, a record for the US tech giant.

Microsoft said the boost in revenues came from pre-sales and upgrades of Windows 8, recognized in the quarter, and gains in business software and other segments.

The second fiscal quarter statement, however, did not offer specific sales data for the Surface tablet launched late last year by Microsoft or its new Windows Phone 8 system, two keys to the company's future.

"Our big, bold ambition to reimagine Windows as well as launch Surface and Windows Phone 8 has sparked growing enthusiasm with our customers and unprecedented opportunity and creativity with our partners and developers," said Steve Ballmer, chief executive.

"With new Windows devices, including Surface Pro, and the new Office on the horizon, we'll continue to drive excitement for the Windows ecosystem and deliver our software through devices and services people love and businesses need."

The profit amounted to 76 cents per share -- one cent better than the Wall Street consensus. Microsoft shares traded down 1.4 percent in after-hours exchanges.

John Ogg at 24/7 Wall Street called it a "mixed" report and said there appeared to be concerns that Microsoft did not offer guidance other than that its operating expenses would be in the $30.3 to $30.9 billion range for the fiscal year.

"Until guidance is offered in the call we would consider this unfinished business," he said.

Citi analyst Walter Pritchard said Microsoft was on target.

"This was the first time in memory we haven't seen disappointment in the Windows line," he said in a research note, maintaining a buy rating.

Raimo Lenschow at Barclays said the results were "essentially in line with investors' low expectations."

The analyst said Microsoft shares would "pull back only modestly" and that investors will be "looking for further detail on what management expects for Windows 8 moving forward" and sales figures for the Surface.

Microsoft said its Windows division saw revenues jump 24 percent to $5.88 billion and that over 60 million Windows 8 licenses had been sold to date.

Gains in online services, server and enterprise software helped offset a decline in the entertainment division which produces the Xbox console and games.

Windows remains the dominant platform for personal computers, but Microsoft has lost ground to Google and Apple in newer devices which use rival operating systems.

The company's search and online services have struggled, but its Xbox is the hottest gaming system in the industry.