Activist hedge fund Irenic Capital Management believes News Corp. should split itself and plans to oppose any deal that undervalues the media company, which is analyzing a potential merger with Fox Corp.

Last week, News Corp. said it would review a proposal from media mogul Rupert Murdoch to combine with Fox Corp, a deal that would bring back the media giant that was split apart nearly a decade ago.

However, Irenic favors a separation of News Corp.’s online real estate listings business from its media assets, which include The Wall Street Journal and The New York Post, according to several media reports.

The activist “looks forward to engaging with the company’s special committee to ensure it explores all paths to maximizing value, including a separation of its preeminent digital media and digital real estate assets,” Irenic co-founder Adam Katz told The New York Times.

Katz worked as a senior analyst at Elliott Management before setting up Irenic last year with Andy Dodge, a former partner at Indaba Capital Management.

Irenic, which owns a stake of about $150 million in News Corp., has engaged with the Murdoch family and believes a split could unlock value as investors would have more clarity on each of the two segments. Irenic reckons News Corp. has a sum-of-the-parts value of $34 a share and plans to push against any transaction that undervalues the company.

News Corp. shares were up 5.3% as of 11 a.m. EDT Monday in New York, with the market value sitting at $9.5 billion. Those of Fox were down 8%, giving it a market capitalization of about $15.3 billion.

Murdoch controls 40% of the voting stock of each company and acts as chairman of both. His son Lachlan is co-chairman of News Corp. and serves as executive chairman and CEO of Fox. However, News Corp.’s bylaws leave Murdoch’s family trust with just 13% of the voting rights on a potential merger with Fox, a person familiar with the matter told Insightia.

Moreover, combining the two media companies would require approval from disinterested shareholders, leaving sufficient maneuvering space for an activist looking to derail such a deal.