Plans by New York powerhouses Sullivan & Cromwell and Paul, Weiss, Rifkind, Wharton & Garrison to open offices in Houston aren't surprising, considering how many Big Law firms with New York ties operations are already established in the city—the hub of the U.S. energy industry. Of the firms ranked in the top 30 of the Am Law rankings, only seven don't have Houston offices—and that number will soon drop to five, when Sullivan & Cromwell and Paul Weiss open their doors. That segment of the Am Law 200 has deep roots in New York, where two-thirds of the top 30 firms operate their largest office. But considering the trends, it may just be a matter of time before even more Big Law firms in New York launch in Houston. Much of the attraction is related to the energy industry, which provides transactional and finance work, along with litigation across the industry spectrum ranging from oil and gas to power to energy transition to data centers. Texas also boasts a business-friendly environment, which has attracted corporate headquarters. And, in many cases most significantly, Big Law firms with expansive client lists already have a roster of clients in Houston, and see opportunities for gaining more work. "Generally, it's 100% driven by deep clients relationships in the energy space. That's not just New York relationships, but worldwide relationships," said Robert Kinney, the president of Kinney Recruiting who places partners in Big Law firms in Texas. Kinney said firms that are not currently in the Houston market, or haven't yet built up large offices, have much potential to grow in the market, "It would be odd to want to be known as a market leader in energy and not be in a place like Houston," added Kent Zimmermann, a strategic advisor with Zeughauser Group. The sustained movement of New York firms into the Houston market has, for around the last two decades, led to strong demand in lateral hiring as the newcomers seek to hire partners from either large homegrown firms or competitors with large offices. Who's Left? Houston, the nation's fourth-largest city by population, has been a favored expansion location for more than four decades. Among early Big Law outposts, Mayer Brown opened an office there in 1982, Weil, Gotshal & Manges in 1985, Baker & Hostetler in 1990, and Skadden, Arps, Slate, Meagher & Flom in 1993. Currently, the top 30 Am Law firms without Houston offices (or announced plans to open one) are Ropes & Gray, Davis Polk & Wardwell; Goodwin Procter; Cooley; and Milbank. Law.com reported in January that New York-founded Sullivan & Cromwell would open an office in Houston, and has hired a Kirkland & Ellis lawyer for the launch. A spokesperson for the firm did not respond to a request for further details on the opening, which would give the global firm its 14th office. Paul Weiss announced on Feb. 3 that it would open an office in Houston, led by Kirkland & Ellis M&A partner Sean Wheeler, who will serve as co-chair of global M&A and head of the new office, and his longtime colleague and fellow Kirkland M&A partner Debbie Yee. Scott Barshay, the new chair of Paul Weiss, said in a recent interview that the firm has wanted to be in Houston for years, and came very close to it a couple years ago, but it didn't happen. The firm continued to "look for the right opportunity," he said, and after a very long courtship, Wheeler agreed to make the move. Houston is important to the 15th-ranked Am Law firm because it has the largest number of public companies outside New York; along with London and New York, it is also one of the three top infrastructure hubs, and is the energy capital of the world, while Paul Weiss has a lot of energy clients, he pointed out. Paul Weiss is an "incomplete law firm" without a major presence in Houston, he said. 'Renewed Strategic Importance' Other Big Law firms have moved into the hot Texas market already this year, and not only in Houston. Dechert opened in Houston and Dallas in January. Latham & Watkins announced the hiring of two Dallas litigators—Winston & Strawn partner Scott Thomas and Kirkland & Ellis partner Taj Clayton, who will serve as chair of Latham's litigation and trial department in Texas—ahead of a planned office opening in Dallas. Weil Gotshal opened an office in Austin, led by Jeff Homrig, a co-head of the firm's intellectual property, technology and science litigation practice, who joined the firm last summer from Latham and had been working out of other Texas offices. The migration to Texas this year hasn't been limited to the very largest firms, either. Freeman Mathis & Gary opened a second office in Dallas, adding a five-partner group from Thompson, Coe, Cousins & Irons, with plans to also launch in San Antonio. And Second Hundred firm Smith, Gambrell & Russell expanded into Houston, hiring commercial litigator Mitch Ackal from Gray Reed. But lately, Houston has clearly been on the radar of the largest firms. Zimmermann said law is a follow-the-money profession, and there is an outsize amount of money coming to Houston. The city not only has one of the largest economies in the U.S., but it is the epicenter of an important industry sector that drives growth in the U.S., he said, adding that oil and gas has "renewed strategic importance" in the current geopolitical environment.