Minneapolis law firm Lindquist & Vennum will merge with Ballard Spahr, a Philadelphia white-shoe firm that dates back more than a century.

Effective Jan. 1, Lindquist's offices will take the Ballard Spahr name and become that firm's largest office outside Philadelphia. The combined firm will have more than 650 lawyers in 15 offices across the country.

The merger is expected to expand the service offerings of Lindquist & Vennum as well as enhance Ballard Spahr's capabilities, especially in the areas of private equity and mergers and acquisitions.

Ballard Spahr will also get its first offices in the Midwest. Most of its offices are on the coasts, though it also operates in Colorado, Utah and Arizona.

Lindquist's Minneapolis location currently has more than 100 attorneys. Lindquist's offices in Denver and Sioux Falls are also part of the deal.

"Lindquist & Vennum is a first-rate law firm with considerable strength in areas we want to expand," Mark Stewart, Ballard Spahr's chairman, said in a statement.

He added that the variety of businesses in the Twin Cities "matches up well with our combined talents."

"Most importantly, the Lindquist lawyers are smart, creative and genuinely nice people. On every level, this combination feels right," Stewart said.

Started in 1968, Lindquist & Vennum advises clients on corporate mergers and acquisitions, and finance and litigation matters as well as other services.

"We are excited to join a forward-thinking firm like Ballard, whose attorneys share our view that client relationships are strategic partnerships," said Dennis O'Malley, Lindquist & Vennum managing partner. "Lindquist has been courted by a number of firms, and we have kept our clients' interests front and center."

Last fall, Lindquist moved into new, modern offices at the IDS Center in downtown Minneapolis.

Lindquist's merger follows a trend of law firm acquisitions that has played out nationwide.

Last year, Minneapolis law office Oppenheimer Wolff & Donnelly consolidated with larger Philadelphia-based firm Fox Rothschild. A couple of years ago, there were discussions of a possible merger of Oppenheimer and Lindquist, but those plans didn't materialize partly because of apparent conflicts between clients.

Nicole Norfleet • 612-673-4495

Twitter: @nicolenorfleet