Breitburn Energy Partners LP is buying Houston-based QR Energy LP for about $1. 6 billion, creating one of the largest master limited partnerships focused on oil exploration and production.

The companies estimated the total value of the transaction at $3 billion, including debt and outstanding Class C convertible preferred units. The transaction has been approved by the boards of directors of both companies, including the QR Energy board of directors’ conflicts committee.

Under the terms of the agreement, QR Energy’s unit holders would receive 72 million Breitburn shares valued at 0.9856 in exchange for each of QR Energy’s shares, according to a news release. That represents a 19 percent premium over the target’s closing price on Wednesday.

The deal comes amid a wave of mergers and acquisitions, initial public offerings and divestitures in the domestic oil and gas markets in recent years that have enriched the coffers of law firms with a Houston presence, as previously reported by The American Lawyer.

Latham & Watkins is advising Breitburn on its acquisition, while Vinson & Elkins is representing QR Energy and Bracewell & Giuliani is advising the conflicts committee of the QR Energy board of directors. Gibson, Dunn & Crutcher is counseling UBS as financial adviser to Breitburn.

Serving as in-house counsel for QR Energy and Breitburn are Gregory Roden and Gregory Brown, respectively.

The merger would create a $7.8 billion company with average daily product of 57,300 barrels of oil equivalent per day, the companies said. Halbert Washburn, Breitburn’s chief executive officer, also noted that it would reduce expenses and enhance earnings for all unit holders.

“This world-class portfolio of conventional properties in large, oil-rich basins fits perfectly with our asset base,” he said in a statement.

Alan Smith, QR Energy’s chief executive officer, added: “Breitburn has a proven 26- year track record of making big oil fields bigger, and we are excited to see that trend continue with the addition of our extensive inventory of organic growth projects.”

The Latham team for Breitburn was led by corporate partner Sean Wheeler, along with corporate partners Michael Dillard and Steven Stokdyk. Financing partner Dennis Lamont, environmental partner Joel Mack, tax partners Tim Fenn and Laurence Stein and benefits and compensation partner David Taub also advised on the matter. Associates Chris Little, Ryan Lynch and Jayne Wabeke assisted.

Latham has represented Breitburn in numerous transactions, including the company’s purchase of Wyoming natural gas and oil producing properties from Cabot Oil & Gas Corporation for $283 million in 2011.

The Vinson & Elkins team for QR Energy was led by corporate partners Jeff Floyd and Jeff Malonson, along with Ramey Layne. Also advising were tax partner Ryan Carney; oil and gas partner Tres Cochran; compensation and benefits partner David D’Alessandro; litigation partner Michael Holmes; environmental law partner Larry Nettles and counsel Larry Pechacek; and antitrust partner Billy Vigdor. Associates on the matter were Benji Barron, Matthew Dobbins, Atma Kabad, Shaun Mathew, James Melchers, Dennis Schmelzer, Atman Shukla, Missy Spohn, Jared Whalen and Matt Wiener.

Vinson & Elkins represented QR Energy in its IPO in Dec. 2010 for $345 million, according to the company.

Vinson & Elkins itself has been a dominant player in the energy market, representing energy companies and private equity firms in 96 major transactions valued at $168.1 billion between 2009 and 2013, according to report in January by The Houston Chronicle. (Latham had 58 transactions valued at $179.8 billion.)

Bracewell & Giuliani advised the conflicts committee of the QR Energy board of directors on the Breitburn deal. Corporate partners Gary Orloff and R. Daniel Witschey and associate J. Clay Brett worked on the deal.

Gibson Dunn’s team for Breitburn’s financial adviser UBS includes corporate partner Eduardo Gallardo and associate Evan M. D’Amico.