(Reuters) - Walt Disney Co has agreed to buy a 33 percent stake in the video unit of Major League Baseball's digital arm, MLB Advanced Media, in a deal that values the business at about $3.5 billion, Bloomberg reported, citing a person familiar with the matter.

Bloomberg earlier reported that Disney agreed to buy the 33 percent stake for $3.5 billion.

Disney and Major League Baseball could not be immediately reached for comment.

Disney will also retain a four-year option to buy an additional one-third stake, Bloomberg said. (http://bloom.bg/2993IWQ)

(Reporting by Supantha Mukherjee and Sangameswaran S in Bengaluru; Editing by Savio D'Souza and Leslie Adler)