Dentons, the world’s largest firm by attorney headcount, inked its fifth major tie-up of 2015 shortly before Thanksgiving by agreeing to absorb Luxembourg-based business law firm OPF Partners into its global Swiss verein on Jan. 1, 2016.

The deal caps a month of rapid growth by Dentons, which in mid-November finalized a three-way combination with Australian firm Gadens and Singapore’s Rodyk & Davidson, an accord reached a week after Dentons formalized a landmark union with Chinese legal giant Dacheng.