(Reuters) - Cyber security company Symantec Corp SYMC.O has agreed to sell its business that helps verify the identity of websites to buyout firm Thoma Bravo LLC, people familiar with the matter said on Wednesday, a move that extricates it from a feud with Alphabet Inc's Google GOOGL.O.

Thoma Bravo is planning to merge its own Web certification company called DigiCert with the Symantec unit it will acquire, the sources said, asking not to be identified ahead of an official announcement expected later on Wednesday.

Symantec stands to receive close to $1 billion in an upfront cash payment as a result of the deal, and will retain a minority stake in the new company that is merged with DigiCert, the sources added.

Thoma Bravo and Symantec declined to comment. DigiCert did not immediately return a request for comment.

The Symantec unit has become a point of contention with Google’s Chrome and other Web browser owners, which have criticized the way Symantec validates its Web certificates. Symantec and DigiCert both issue these Web certificates which help verify the identity of websites so that they can be trusted by those browsing the Internet.

Google demanded major changes to the division’s underlying technology and business practices in order for its browser, Chrome, to continue respecting Symantec certificates, and the two sides have been negotiating since then.

Google did not respond to a request for comment on Wednesday.

Symantec acquired most of its Web certification business in 2010, when it paid $1.28 billion to buy Verisign Inc's VRSN.O security business. Thoma Bravo bought a majority stake in DigiCert in 2015 for an undisclosed sum.

The sale comes more than a year after Symantec parted with its data storage business Veritas in a $7.4 billion deal with private equity firm Carlyle Group LP CG.O.

Under Chief Executive Officer Greg Clark, Mountain View, California-based Symantec has been one of the few cyber security companies to pursue large deals.

Symantec completed its $2.3 billion acquisition of LifeLock Inc in February, a move that bolstered its consumer security business. That followed the purchase of Blue Coat Inc for $4.65 billion last year, which expanded its product line for large corporations.