Shares of Howard Hughes rose Monday but were below Ackman’s offering price. It may take more from Pershing Square to seal a deal.

Shares of Howard Hughes Holdings jumped after hedge-fund manager Bill Ackman's firm offered to buy 11.8 million Howard Hughes shares at $85 apiece to own a majority stake in the company. The stock jumped about 9.

Billionaire Bill Ackman is offering to take over Howard Hughes Holdings, with the goal of turning the Houston real estate firm into a holding company akin to Warren Buffett's Berkshire Hathaway. Ackman's Pershing Square Capital Management is seeking to own as much as 69% of Howard Hughes Holdings,