cuban_mark050517BREAKING NEWS! UPDATE: Lionsgate insiders tell me: “This isn’t a big surprise and doesn’t change the dynamics of the Icahn takeover fight.  Cuban was one of Icahn’s nominees for the Yahoo Board of Directors in 2008, and we always thought it was likely he would tender to Icahn.  We think if he does tender to Icahn at seven dollars a share, he’s leaving money on the table.”

Noon: Carl Icahn scored another huge victory in his hostile takeover battle for Lionsgate. Then again, Mark Cuban is one of the kookiest entrepreneurs out there and may just be seeking publicity at Lionsgate bosses’ expense or a negotiating advantage with the studio for board seats, movie and TV deals, icahn lgaccess to the sizeable library, etc. Until today, Icahn had not been able to get traction with Lionsgate stockholders for his $7-a-share tender offer. But what Cuban said this morning on CNBC is “I really think I’m going to tender and I will have a conversation with them today… I have my reasons I don’t want to get into. But I think it’s the right move for right now and the right move for the long term, for the company and me.”

With Cuban’s shares, Icahn would become Lionsgate’s largest shareholder. Cuban owns 5.3% of Lionsgate shares, and Icahn already owns nearly 19%. To date, only about 4% of the studio stockholders had agreed to tender to him despite Icahn extending the offer, which now expires on June 16th. So, altogether, Icahn could own at least 28% of Lionsgate stock. Meanwhile, Lionsgate management have seemed to exhaust their defenses against him. Their attempt to put in place a poison pill was foiled by a British Columbian regulatory body, and a Canadian court rejected Lionsgate’s appeal of the decision. (Santa Monica-based Lionsgate is both U.S. and Canadian operated.) The studio keeps urging shareholders to give Icahn’s offer cold shoulder, and they have. But if Cuban decides to back Icahn, it could influence other stockholders.

Meanwhile, the effect on Hollywood is that Lionsgate is now a destabilized studio and staff there are fearful.

I’ll have exclusive reporting on this developing story within the hour.

Editor-in-Chief Nikki Finke - tip her here.

For all of Deadline's headlines, follow us @Deadline on Twitter.