AT&T Corp. is expected to announce Tuesday that it will license its speech-processing technology to SpeechWorks International Inc., a provider of speech-recognition software, in a bid to capture a share of that fast-growing market.

As part of the deal, AT&T has purchased a minority stake in SpeechWorks, a Boston service provider that recently registered for an initial public offering. Financial terms weren’t disclosed. Speech-recognition technology is most commonly used in voice-activated telephone menus such as directory-assistance offerings that allow a caller to obtain information by saying a city or business name. In recent months, however, Internet companies have turned their attention to technology to allow callers to retrieve Web content by speaking voice commands using a telephone. Industry observers say the technology is expected to drive wireless-data offerings that will make it simple for users to use the Web without being tethered to a desktop. Dave Nagel, AT&T’s chief technology officer, said AT&T has been working on speech-processing technology for about 30 years and has invested some $50 million to $100 million in it. But the communications giant is not in the business of developing speech-recognition products and services. It will depend on SpeechWorks to bring the services to market. SpeechWorks will gain access to AT&T’s research, and AT&T will receive discounts on products that SpeechWorks develops. Both AT&T and SpeechWorks will jointly market the services to AT&T’s customer base.