** Shares of AI firm Brand Engagement Network BNAI.O (BEN) rise 8% to $20.59 premarket

** Co says INTERVENT Health AI combines BEN's conversational AI with INTERVENT's coaching programs used by 150-plus medical centers and employers

** Joint venture will focus on managing chronic diseases such as diabetes and heart conditions using AI-guided coaching, BEN says

** BEN to act as exclusive AI provider in North America for at least five years, co says

** Says INTERVENT brings health data and programs with 2 million users and evidence from 120-plus studies

** BEN expects revenue from software licensing and commercialization services, co says

** As of last close, stock up about eightfold YTD