(Adds details on deal, background on Sharecare)

Feb 12 (Reuters) - Digital health startup Sharecare Inc said on Friday it has agreed to go public through a merger with a blank-check firm backed by veteran investment banker Alan Mnuchin, in a deal that values the combined company at $3.9 billion.

The deal will be funded with a $425 million private investment, led by Koch Strategic Platforms, Baron Capital Group, Eldridge and Woodline Partners LP.

Mnuchin, brother of former U.S. Treasury Secretary Steve Mnuchin, is a former vice president of Goldman Sachs and the founder of New York-based investment bank AGM Partners LLC.

Sharecare's deal with Falcon Capital Acquisition Corp

is the latest among app-based healthcare providers taking the SPAC route to go public.

Online therapy app Talkspace said on Jan. 13 it will go public through a $1.4 billion deal with Doug Braunstein-backed blank-check firm Hudson Executive Investment Corp .

Reuters, citing sources, reported on Jan. 26 that Sharecare was in talks to merge with an Alan Mnuchin-backed special purpose acquisition company (SPAC), in a deal that could value the combined entity at nearly $4 billion.

Founded in 2012 by WebMD founder Jeff Arnold, Atlanta-based Sharecare is an online healthcare platform that provides its customers with advice on health and lifestyle-related matters. Arnold will continue to lead the merged entity as chief executive officer.

SPACs like Falcon are shell companies that raise funds through an initial public offering $(IPO.UK)$ to acquire a private company, which becomes public as result. Falcon raised $345 million in an IPO in September last year.

Sharecare will be listed on the Nasdaq after the merger and will trade under the new ticker symbol "SHCR".

(Reporting by Sohini Podder in Bengaluru; Editing by Shinjini Ganguli)

((sohini.podder@thomsonreuters.com;))