* Unibail Rodamco offers $7.55 a share, 18 pct premium
* Westfield recommends "highly compelling" bid
* Westfield owns 35 shopping centers in UK, U.S. (Recasts with bid, previous media slug WESTFIELD-DEALS/)
SYDNEY/MELBOURNE Dec 12 (Reuters) - France's Unibail-Rodamco has agreed to buy shopping mall owner Westfield Corp for $24.7 billion including debt, in what would be the biggest takeover of an Australian company on record.
Westfield, which owns and operates 35 shopping centers in the United States and United Kingdom valued at $32 billion, said the transaction was "highly compelling" for Westfield and Unibail-Rodamco's shareholders.
"Unibail-Rodamco's track record makes it the natural home for the legacy of Westfield's brand and business," Westfield Chairman and co-founder Frank Lowy said in a statement.
Unibail-Rodamco said putting the two companies together would create a global property leader with $72 billion of gross market value, strategically positioned in 27 of the world's most attractive retail markets.
Westfield's flagship malls include Westfield London, where it is working on a 600,000 pound ($800,000) expansion, and Century City in Los Angeles, where it is completing a $1 billion overhaul.
It also has stakes in 18 suburban U.S. shopping centers, three of which it wholly owns.
Unibail Rodamco said Westfield shareholders would receive a combination of cash and shares, valuing Westfield at $7.55, or A$10.01 a share, an 18 percent premium to Westfield's last trade.
Shares in Westfield were halted earlier on Tuesday pending the announcement, having last traded at A$8.50. (Reporting by Byron Kaye and Swati Pandey in Sydney and Sonali Paul in Melbourne; Additional reporting by Susan Mathew in Bangalore; Editing by Stephen Coates)