Wachtell, Lipton, Rosen & Katz advised United Technologies Corp. in an all-stock purchase of U.S. defense contractor Raytheon Co., which was represented by Shearman & Sterling in one of the largest transactions ever in the aerospace industry.

Connecticut-based United Technologies agreed to purchase Raytheon Co. on Sunday in an all-stock deal, creating a new aerospace and defense company with $74 billion in sales and worth well over $100 billion.

The new entity will be called Raytheon Technologies Corp. after United Technologies completes the separation of its Carrier air-conditioner and Otis elevator businesses, the companies said in a statement.

The deal, which is billed a merger of equals, is expected close in the first half of 2020.

United Technologies Corp. was advised by longtime outside counsel Wachtell, with firm cofounder Martin Lipton, along with corporate partners Joshua Cammaker, Edward Lee and Victor Goldfeld leading the deal team.

Antitrust partner Damian Didden, executive compensation and benefits partner Jeannemarie O’Brien and tax partner T. Eiko Stange also advised on the deal. Five associates also joined the Wachtell team on the transaction.

Wachtell’s work with United Technologies has included advising the conglomerate on its $23 billion acquisition of Rockwell Collins Inc. in 2017. The firm also advised the defense contractor on its $18.4 billion purchase of aircraft equipment manufacturer Goodrich Corporation in 2011 and its $1.8 billion purchase of General Electric’s firm alarm and security unit in 2009.

Shearman & Sterling corporate partners Clare O’Brien, Sean Skiffington and Cody Wright lead the deal team for Raytheon, along with compensation, governance & ERISA partner John Cannon.They were joined by antitrust partners David Higbee and Matthew Readings and counsel Sara Ashall; litigation partners Alan Goudiss and Mallory Brennan; and intellectual property transactions partner Jordan Altman along with nearly a dozen associates.

Crowell & Moring served as lead U.S. antitrust counsel to United Technologies, with partner Shawn Johnson and counsel Lauren Patterson and Martin Mackowski leading the team.