Financial terms of the agreement were not disclosed. Fox acquired 49 percent of the YES Network in December 2012, and it was reported that Fox paid $584 million for that stake.
"Clearly, 21st Century Fox is a great partner for us as the YES Network fulfills and expands its potential as one of the nation's premier regional sports networks," Yankees managing general partner Hal Steinbrenner said in a statement. "We are gratified that 21st Century Fox has increased their stake and investment in the network. Yankee Global Enterprises is eager to continue working with 21st Century Fox as we explore ways to take YES to even greater heights."
Fox also announced that Tracy Dolgin, who is president and chief executive officer of the YES Network, will remain in his role leading the network.
"Our investment in the YES Network underscores our commitment to growing our global sports portfolio with offerings that are exceptional and unique," said James Murdoch, the deputy chief operating officer of 21st Century Fox. "We look forward to expanding our partnership with Yankee Global Enterprises and to working with the network's management team to build on the YES Network's success."
Launched in 2002, the YES Network delivers exclusive live local television coverage of Yankees baseball and Brooklyn Nets basketball, as well as other Emmy Award-winning local and national sports programming. It is available in approximately nine million homes in New York, Connecticut, New Jersey and parts of Pennsylvania, plus being nationally available on several cable and satellite television distributors.
The acquisition is expected to be completed by March 31, subject to approvals.
Bryan Hoch is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.