Microsoft Corp showed off prototype phones featuring its new mobile software to Wall Street analysts on Thursday, but is yet to set a date for their rollout beyond availability this holiday shopping season.

The devices aim to claw back market share lost to Apple Inc and Google Inc in the rapidly growing smartphone market, and are a key test for Microsoft's ability to compete in the consumer electronics market.

It's probably fair to say we've got a lot of work to do, said Chief Executive Steve Ballmer at the company's annual presentation to analysts at its Redmond, Washington headquarters. It isn't all going to happen overnight.

Microsoft employees showed off the new phones running Windows Phone 7, made by handset makers Samsung Electronics Co and LG Corp, but did not allow photographs of the devices, which are still at the prototype stage.

No handset makers have announced a date for commercial launch. Ballmer said only that they would be coming to market this autumn.

The devices have large touch screens, incorporate a Zune music player, e-mail programs and link up with content from Xbox Live, Facebook, and other networks.

Microsoft is also ready to forge ahead on new slate computers running Windows 7, to counter the growth of Apple's hot-selling iPad, said Ballmer.

We've got to push right now with our hardware partners, said Ballmer. They (the new slate devices) will be shipping as soon as they are ready. It's job No. 1 urgency around here. Nobody's sleeping at the switch.

Both the phones and slates will have aggressive marketing support, Ballmer said. The new slates should also get a boost from Intel Corp's new range of chips expected early next year, he added.

(Reporting by Bill Rigby; Editing by Tim Dobbyn)