Microsoft on Wednesday ramped up its push to regain ground in the precious mobile computing market by giving developers a "sneak peek" at new Windows software for smartphones.

A key feature of Windows 8 Phone is that it will be keenly in tune with the similarly named next-generation operating system for personal computers as the technology titan creates a stage on which popular devices can play together.

"It's the most advanced mobile OS Microsoft has ever made and will arrive on new phones later this year," said Windows Phone program manager Joe Belfiore.

"Windows Phone 8 is based on the same core technologies that power Windows; the most successful and powerful operating system on the planet, and one used by more than a billion people."

The early glimpse at Windows 8 Phone came at a gathering of software developers and press in San Francisco a day after Microsoft set the technology world abuzz by unveiling its own tablet computer to challenge Apple's iPad.

"If you've seen Windows 8, Microsoft's groundbreaking new release for PCs and tablets, you've probably noticed it bears more than a passing resemblance to the look of Windows Phone," Belfiore said.

"Windows Phone and its bigger sibling will share common networking, security, media and web browser technology, and a common file system."

Microsoft introduced its first tablet computer, the Surface, on Monday, in a major hardware launch clearly designed to take on long-term rival Apple's market-ruling iPad.

Chief executive Steve Ballmer described the iPad challenger -- complete with a built-in stand and ultra thin covers-cum-keyboards in a range of colors -- as a tablet that "works and plays."

"The Surface is a PC, the Surface is a tablet, and the Surface is something new that we think people will absolutely love," he said at an hour-long presentation in a Hollywood design studio.

No prices or release dates were given, but the Surface is expected to go on sale in the fall, with retail prices "competitive with a comparable ARM tablet or Intel Ultrabook-class" computers, Microsoft said.

The Redmond, Washington-based technology firm has seen Apple and Google-backed Android gadgets commandeer the smartphone and tablet markets at a time when lifestyles are shifting away from desktop computers to mobile devices.