The goal of both is to give people an easier way to find the latest news online in an easily digestible form.
Microsoft said its service aims to be a "personal newsstand" that will heed user preferences while culling data from more than 4,800 English-language news outlets.
Google's news site scours 4,500 English-language news outlets. The Google site, which is also still officially in a test form, has been around in various iterations since late 2001.
The test version of Newsbot was launched as part of MSNBC.com, a news Web site that is a partnership with Microsoft and NBC News. Justin Osmer, a product manager with Microsoft's MSN online division, said Newsbot will be available for a limited amount of time so the company can gather feedback.
It will then be taken down and replaced by the final version.
Redmond-based Microsoft earlier began testing Newsbot in international markets as part of its MSN online service, and said it also planned to launch the technology in the United States.
The move is part of Microsoft's aggressive, $100 million fight to establish a stronger foothold in the hot field of search--an area where Microsoft admits it initially missed the boat.
Earlier this month, Microsoft launched a test version of its own, more general Internet search technology, with plans to have a final version within a year. Currently, Microsoft uses Yahoo Inc.'s search technology for its MSN Web site.
The company also greatly simplified its MSN search Web site, creating a clean look that mimics Google's main search site.
Microsoft's longer-term plans include a broader search technology that would let people search Web sites, e-mails and even big databases.
The launch of Newsbot comes a day after Google disclosed more details of its highly anticipated public stock offering, which could give the company a market value of as much as $36 billion.
Google plans to offer 24.6 million shares for $108 to $135 each.