As online retailers put the pinch to traditional brick-and-mortar shops, Europe’s largest commercial landlord announced on Dec. 12 that it would acquire Australian mall owner and operator Westfield Corp. Ltd. in a roughly $25 billion deal that has yielded roles for more than a dozen outside law firms.

Unibail-Rodamco SE has agreed to absorb Sydney-based Westfield in a $15.8 billion cash-and-stock deal that the acquirer expects will close in the first half of 2018. Shearman & Sterling and Clifford Chance are counseling Paris-based Unibail-Rodamco on the proposed transaction, along with other teams of lawyers from France’s Capstan Avocats and Darrois Villey Maillot Brochier, Dutch firm NautaDutilh and leading Australian firm Allens.