Pittsburgh-based K&L Gates has opened an office in Houston with the addition of corporate partner Charles L. Strauss.

It’s the firm’s 47th office overall and fourth Texas office, along with Austin, Dallas and Fort Worth.

Strauss comes to the firm from the Houston office of Fulbright & Jaworski, where he was a partner since 1991 and head of the securities practice group.

Strauss’ corporate and securities practice focuses largely on mergers, acquisitions and divestitures, public and private securities, corporate restructuring, joint ventures and international law, among other areas.

His client base is spread across a number of energy and infrastructure industries, including oil and gas exploration, production, service, refining, pipeline and marketing.

Strauss also does work for clients in the chemical and petrochemical, information technology, aerospace, helicopter, trucking and financial services industries.

In a press release, the heads of the K&L Gates’ energy, infrastructure and resources practice area — Seattle partner Elizabeth Thomas, Pittsburgh partner Michael Zanic and Perth, Australia, partner Simon Salter — were quoted as saying the establishment of a Houston office “cements our firm’s presence across the globe in energy, infrastructure and resources.”

“With Charles anchoring our Houston office, K&L Gates can serve existing clients even better while also broadening our work in the sector,” the group said in the press release.

K&L Gates has been increasingly focused on the energy sector in recent years, having established the EIR practice in 2011. The firm even moved Zanic out of his previous position as administrative partner of its Pittsburgh office so that he could co-lead the group.

K&L Gates’ chairman and global managing partner, Peter J. Kalis, said in a press release that the firm would work with Strauss “to grow a dynamic and client-focused Houston office.”

The firm declined to comment beyond the press release on Monday.

The firm’s announcement of the Houston office comes about three weeks after Pittsburgh-based Reed Smith announced that it was opening a Houston location.

Reed Smith has remained mum on who will be joining the office, but, like K&L Gates, has confirmed that it is building the office from the ground up rather than through a merger.

Gregory B. Jordan, Reed Smith’s global managing partner, told The Legal in January that the firm had originally been looking for a firm to merge with in Texas, but that, because of conflicts or just a differing view of where the market was headed, talks with several key Texas firms didn’t work out. The firm’s merger discussions with Texas-based Thompson & Knight, for example, were made public in late 2010 but ended in early 2011. Jordan said Reed Smith really liked the firm, but couldn’t get the deal done.

So nearly two years later, Reed Smith began building out its own office space in downtown Houston a few months ago, according to reports from Legal affiliate The Am Law Daily.

With the addition of K&L Gates’ and Reed Smith’s office openings, there are now 11 Pennsylvania firms that have Houston locations, according to Legal affiliate PaLaw.

Morgan, Lewis & Bockius, Cozen O’Connor, Blank Rome, Duane Morris, Jones Day, Littler Mendelson, Greenberg Traurig, DLA Piper and McGuireWoods all have Houston locations.

Meanwhile, the past few years have also seen several Houston-based firms either entering or expanding in Western Pennsylvania in order to capitalize on the oil and gas work being generated by the Marcellus and Utica shale plays.

In December 2011, Houston-based energy law boutique The Sadler Law Firm opened an office in the Southpointe business park in Washington County, Pa.

In April 2011, Fulbright & Jaworski added six energy lawyers from K&L Gates, including partner Kenneth S. Komoroski, to open its Southpointe office.

Before that, in September 2010, Houston-based Burleson LLP expanded its Southpointe office with the addition of partner Kevin L. Colosimo from Thorp Reed & Armstrong and several associates from Hogan Lovells, Meyer, Unkovic & Scott and Reed Smith.

Zack Needles can be contacted at 215-557-2493 or zneedles@alm.com. Follow him on Twitter @ZNeedlesTLI.