The Walt Disney Company is in talks with the Spanish-language broadcaster Univision to sell its stake in Fusion, the joint venture started by the two companies two years ago, a person with knowledge of the discussions said Tuesday.

Fusion is an English-language digital news service and cable channel that is aimed at millennial audiences. Its chief executive is Isaac Lee, who also oversees digital and multicultural functions at Univision.

Terms of Disney’s exit, including the timing, the price and whether other partners were involved, were not clear.

Over the years Fusion has struggled to define its identity and deliver large audiences. The cable channel has faced challenges attracting viewers in an era when TV networks face sharp ratings declines, particularly among younger viewers. The website, which originally was aimed at young Latinos who spoke English but shifted to target young viewers of all ethnicities, has had a hard time standing out against digital media rivals like BuzzFeed and Vice.