U.S. mall owner GGP has rejected Brookfield Property's $14.8 billion buyout offer. In this image, a pedestrian passes a hoarding surrounding the construction site of Principal Place, a joint development by Brookfield Property Partners LP, Concord Pacific and W1 Developments, in London.

GGP, one of the largest owners and operators of U.S. shopping centers, has rejected a $14.8 billion buyout offer from its biggest shareholder, Brookfield Property Partners LP, people familiar with the matter said on Sunday.

Brookfield Property made a $23-per-share cash and stock offer last month for the 66 percent of GGP it does not already own. A combination of Chicago-based GGP and Brookfield Property would create one of the world's largest publicly traded property companies.

Brookfield Property is considering a new offer for GGP after a special committee of GGP's board directors turned down its Nov. 11 offer as inadequate, and negotiations between the two companies are expected to continue, the sources said.

The companies do not plan to make a new announcement unless their negotiations lead to a deal or end unsuccessfully, the sources added, asking not to be identified because the discussions are confidential.

GGP and Brookfield Property did not immediately respond to requests for comment.

Brookfield Property's efforts to buy GGP have come as mall owners across the United States are struggling as a result of many retailers losing out to e-commerce firms such as Amazon.com.

GGP shares ended trading at $23.43 on Friday, giving it a market capitalization of $22.2 billion. Its shares have underperformed the wider stock market this year because of the company's exposure to troubled retailers such as Sears Holdings.

Brookfield Property Partners shares ended trading on Friday at $21.61, giving it a market capitalization of $15.2 billion.

Brookfield Property, an owner and operator of office and retail properties, said last month the deal would allow it to grow, transform or reposition GGP's shopping centers.

The acquisition would create a company with an ownership interest in almost $100 billion real estate assets globally and annual net operating income of about $5 billion, according to Brookfield Property.

It is not the first time Brookfield Property's attempt to buy out a real estate investment trust in which it already owns a big stake has been rejected. Last year, Rouse Properties, another U.S. mall owner, rejected an offer by Brookfield Property, its largest shareholder, only to subsequently agree to a sweetened $2.8 billion offer.

Other GGP peers are also coming under pressure. Rival mall owner Macerich currently is under pressure from activist hedge fund Third Point Management to explore options including a sale.