Large, small, global and regional — law firms are opening Washington offices at a rate not seen since before the recession, as they position themselves for work centered around the capital’s regulatory machinery.

In the past 10 months, at least seven firms opened D.C. offices: Becker & Poliakoff, Mitchell Williams, Fredericks Peebles & Morgan, Allen & Overy, Sedgwick, Quinn Emanuel Urquhart & Sullivan and Bass Berry & Sims. Another firm, Miles & Stockbridge, is slated to open its K Street office Wednesday.

The firms range dramatically in size and scope, but many have one thing in common: they view Washington as a critical base to grow regulatory and international practices centered around Congress and Washington-based agencies, such as the International Centre for Settlement of Investment Disputes, which hears cases between foreign governments, and the International Trade Commission.

A Washington office “can make clients feel like they have people at the center of the regulatory universe,” said Jeffrey Lowe, managing partner of the D.C. office of legal staffing firm Major, Lindsey & Africa. “There’s a prestige factor there.”

The District has long been home to the nation’s largest regulatory practices, if for no other reason than the fact that government decisions can make or break industries. The fate of a merger, new drug or telecommunications policy can turn on a federal rule. Some of the firms locating here now are establishing practice teams around financial and health-care reforms.

The influx comes as the legal industry emerges from a downturn that saw many big firms shed attorneys and staff. Global law firm Allen & Overy, for instance, in 2009 shelved plans to add a Washington presence. “But as things started to normalize, we became more and more convinced we needed to be in D.C. for the regulatory play,” said U.S. managing partner Kevin O’Shea. The firm opened its D.C. office in June.

“There was a time when there was very little activity because firms were just not investing when the economy was totally uncertain,” said Steve Nelson, managing principle for the law and government affairs groups at the McCormick Group, an Arlington-based executive search firm. “You saw that in 2008, 2009 and even 2010. But now I think leadership of firms have a good idea of the economic trends that affect them, and they’re seeing that D.C. is important because of some of the regulatory and government issues.”

Quinn Emanuel, the 600-lawyer business litigation powerhouse, opened its first Washington office in September after at least six years of searching for attorneys with the right practice, experience and personality fit for the firm, said Faith Gay, co-chair of the firm’s national trial practice group.

Last fall, Quinn Emanuel hired William A. Burck, a former federal prosecutor in New York and deputy counsel to President George W. Bush, from Weil Gotshal to co-head the firm’s D.C. office with longtime Quinn Emanuel partner Jon Corey.

“Our intellectual property practice, international disputes practice and government investigations practice needed this growth,” Gay said. “Washington is a vital linchpin for us in having seamless coverage in these practice areas domestically and internationally.”

Other firms launched D.C. outposts for different reasons.

Sedgwick, the 400-lawyer litigation firm, absorbed Washington boutique firm Wallace Partners to open a District office in August purely to expand litigation capabilities. And Miles & Stockbridge, a 210-attorney regional firm, is more focused on growing transactional work in the Washington manufacturing, financial and real estate industries.

“Clients have indicated if we’re there, they’d send us additional work,” said Miles & Stockbridge chairman John Frisch.