SYDNEY (Reuters) - Shares of Australian shopping mall giant Westfield Corp <WFD.AX> rose as much as 15 percent on Wednesday, their biggest single-day gain, after the company said it would accept a $16 billion takeover offer from France's Unibail-Rodamco SE <UNBP.AS>.
The shares hit a high of A$9.77 after coming out of a trading halt at 0000 GMT before easing to A$9.73, up 14.5 percent, while the broader market was up 0.1 percent.
That was below Unibail-Rodamco's offer of A$10.01, reflecting risks that Australia's biggest company takeover on record may encounter regulatory challenges.
Shares of Scentre Group <SGC.AX>, which Westfield spun off in 2014 to hold its Australian shopping centers while Westfield kept the U.S. and British assets, were up 1.1 percent, on top of the previous day's 4 percent rally amid speculation about the Westfield deal.
The private companies of Westfield Chairman Frank Lowy own about 5 percent of Scentre, according to Thomson Reuters data.
In French trading overnight, shares of Unibail-Rodamco fell 4 percent with analysts at Kepler Cheuvreux saying the deal looked expensive.
($1 = 1.3229 Australian dollars)
(Reporting by Byron Kaye; Editing by Stephen Coates)