Merger talks between Hunton & Williams and Andrews Kurth Kenyon now appear to be in advanced stages, with the law firms signing a merger agreement.

While the deal is not yet final, two sources familiar with the talks say the law firms' management have signed paperwork to proceed with the merger. The timeline for partners to vote on the deal is unclear, though a source previously told ALM that partners would vote this month.

The sources spoke on condition of anonymity because they were not authorized to discuss the deal. An Andrews Kurth spokeswoman declined to comment, as did a spokeswoman for Hunton & Williams.

The proposed merger has advanced despite multiple defections and group exits from Andrews Kurth Kenyon over the last few months. In 2018 alone, Andrews Kurth partners have headed to DLA Piper, Katten Muchin & Rosenman, and Haynes and Boone, while Orrick, Herrington & Sutcliffe is expected to hire a team of public finance lawyers and White & Case and Shearman & Sterling have been in advanced discussions with partners to open offices in Texas.

However, sources knowledgeable about the firms say those exits have not derailed the deal because Hunton & Williams' primary interest has been Andrews Kurth's Houston office, which has strong oil and gas and capital markets practices. Andrews Kurth has about 45 corporate partners in its Houston base alone, according to its online head count figures this week.

Andrews Kurth generated $289 million in revenue in 2016, a drop of 2.7 percent from the year before, while Hunton & Williams grew gross revenue 2.5 percent to $541 million, according to figures from The American Lawyer. Both firms have generated similar revenues per lawyer, with RPL of $820,000 for Hunton and $885,000 for Andrews Kurth in 2016.

Brenda Sapino Jeffreys contributed reporting.