Westfield trading halt considered rare Company owns 35 shopping...

• Westfield trading halt considered rare
• Company owns 35 shopping centres in UK, U.S.
• Analysts say second-tier malls sale possible

(Adds analysts' comments, background)

Dec 12 (Reuters) - Shopping mall giant Westfield Corp (WFD) said on Tuesday it was set to announce a major deal as it sought a trading halt on its shares, triggering speculation it could be selling some of its second-tier U.S. malls or lining up a merger.

The company, which owns and operates 35 shopping centres in the United States and United Kingdom valued at $32 billion, said it was in talks with unnamed parties for a "potentially significant corporate transaction", without revealing further information.

Chairman Frank Lowy would host a media conference in Sydney at 0700 GMT.

Analysts said it was rare for Westfield to seek a trading halt simply to announce a sale of a stake in a mall, suggesting a bigger deal was in the offing.

"They could be selling some of the lower grade assets - called their regional assets," said Morningstar analyst Tony Sherlock, questioning whether that would be big enough to warrant a trading halt.

The company has stakes in 18 regional shopping centres, three of which it wholly owns.

Its flagship malls include Westfield London and Century City in Los Angeles, where it is completing a $1 billion overhaul.

Sherlock and another analyst, who declined to be named, played down speculation in one Australian newspaper that European property group Unibail Rodamco might be eyeing a takeover of Westfield.

They also said it was unlikely that Westfield might be looking to trump a $14.8 billion bid by Brookfield Property Partners LP for GGP Inc , one of the largest owners and operators of U.S. shopping centres.

Westfield shares last traded at A$8.50, valuing the company at A$17.6 billion.