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.

Pershing Square's potential majority stake could influence Howard Hughes' future, but risks remain. See my recommendation on HHH stock.

Pershing Square Capital Management LP has proposed a deal to merge one of its subsidiaries with real estate company Howard Hughes Holdings Inc., according to a letter to investors.

Under the proposed deal, a Pershing Square unit will buy 11.8 million shares for $1 billion from non-Pershing Square affiliate shareholders of Howard Hughes, while the real estate developer will commence a $500 million share repurchase at $85 per share for up to 5.9 million shares.

Pershing Square Capital Management is pushing for a merger after the spinoff of some of Howard Hughes’ other entities.