Kirkland & Ellis has opened a Houston office with the hire of M&A partner Andrew Calder from Simpson Thacher & Bartlett.

The base is Kirkland's twelfth worldwide and seventh in the US, to be led by Calder, who was previously with Simpson Thacher in the city.

Specialising in M&A, securities law and corporate governance, with a focus on the energy sector, Calder's key clients include private equity funds Blackstone Energy Partners and KKR, as well as GeoSouthern Eagle Ford Development, Alta Energy Luxembourg, Arch Coal, Petrohawk Energy Corporation and PPL Corporation among others.

He trained with Herbert Smith in London, but moved to the US with Simpson Thacher in 2004 after qualifying.

Joining him will be two other corporate and private equity specialists; ex-Simpson Thacher lawyer Rhett Van Syoc, and ex-Debevoise & Plimpton lawyer Benjamin Clinger, who is relocating to Houston from Kirkland's Chicago office and who was promoted to partner at the firm last year.

Houston has become increasingly attractive to US and other international firms seeking to tap the coveted Texan market for energy work.

Those to enter the city in the last 18 months include Arnold & Porter, who launched with a four-partner Hogan Lovells team in January, Dentons, which relocated lawyers from Dallas, Washington and Chicago for a September opening, K&L Gates which added a base in February 2013 with the hire of Fulbright & Jaworski's head of securities, and Reed Smith, which launched in January last year prior to making an appointments.

Others to have opened since 2011 include Paul Hastings, Sidley Austin, Cadwalader Wickersham & Taft and Simpson Thacher & Bartlett, joining more established Houston energy firms such as Vinson & Elkins and Baker Botts.

Kirkland now has seven offices in the US including Houston, New York and Los Angeles, Washington DC, Palo Alto, San Francisco and its headquarters in Chicago.

International bases include London, Munich, Shanghai, Hong Kong and Beijing, with that in the Chinese capital opening in September last year.

In Hong Kong the firm has also made several key hires to ramp up its offering, with the addition of eight partners in 2011 from Skadden Arps Slate Meagher & Flom, Latham & Watkins and Allen & Overy (A&O), and the recruitment of M&A specialist Frank Sun from US rival Paul Weiss Rifkind Wharton & Garrison in January last year.