(Reuters) - Paramount Global ( PARAA ) is in talks about opening its books to a consortium of Sony Pictures and buyout firm Apollo Global Management ( APO ) interested in acquiring the U.S. media company, people familiar with the matter said on Wednesday.

Advisers to both sides are discussing the terms of a confidentiality pact that allows the exchange of commercially sensitive information, the sources said. Doing so would pave the way for Apollo and Sony ( SONY ) to firm up their $26 billion offer and challenge a rival bid from David Ellison's Skydance Media.

A special committee of Paramount's board that is evaluating the company's options allowed an exclusivity period to lapse in its deal discussions with Skydance last week.

The sources requested anonymity because the matter is confidential and cautioned there was no guarantee the talks would lead to a deal.

A spokesman for Paramount's special committee declined to comment.

Sony Pictures Chairman Tony Vinciquerra first approached Paramount's controlling shareholder, Shari Redstone, years ago to explore acquiring the Paramount Pictures film studio, according to two sources familiar with the talks. At the time, Redstone was not interested in breaking up the company, one of the sources said.

Since then, Sony ( SONY ) has been expanding its entertainment business, which spans film, music and television production, as well as distribution and publishing.

Sony Pictures has more than 3,500 movies in its library, including such franchises as "Jumanji", "Resident Evil" and "James Bond."

Combining with Paramount, which is home to "Star Trek", "Top Gun" and "The Godfather," would create a Hollywood studio with the box office heft of Universal Studios or Walt Disney Studios.

A tie-up between Sony ( SONY ) and Paramount would give it a 20.5% share of the North American box office, according to Comscore's market share analysis, using 2023 ticket sales.

Skydance had proposed a complex transaction, in which it would pay roughly $2 billion to acquire the Redstone family's holding company, National Amusements, which holds 77% of Paramount's class-A voting stock.

Paramount would then acquire Skydance in an all-stock transaction worth around $5 billion. It subsequently offered a $3 billion deal sweetener entailing a mix of share buybacks and cash that could be used to pay down debt.