Cleary Gottlieb Steen & Hamilton and Simpson Thacher & Bartlett are advising on a multibillion-dollar deal that will see Japanese and South Korean tech giants SoftBank and Naver Corp. embark on a joint venture.

SoftBank said in a statement that its subsidiary, Yahoo Japan, which changed its name last night to Z Holdings Corp., will merge with Naver-owned Line Corp., creating an internet giant. The deal will create a $30 billion business, according to Reuters.