Wachtell, Lipton, Rosen & Katz is representing Univar Inc. on its pending $2 billion buy of smaller rival Nexeo Solutions Inc., which has turned to Weil, Gotshal & Manges for outside counsel on the matter.

Vinson & Elkins is advising buyout firm TPG Capital, a Nexeo stockholder, on the transaction. Univar, based in Downers Grove, Illinois, and The Woodlands-based Nexeo announced an agreement on Sept. 17 calling for Univar to acquire Nexeo in a cash-and-stock deal valued at about $2 billion, including the assumption of Nexeo’s debt and other obligations.