L-R: Hunter Kintzinger, Jeffrey J. Pustizzi and Catharine Elizabeth Sibel of Rittenhouse Law.

The Philadelphia region has seen its fair share of law firm openings this year.  Now another has joined the pack of young, hungry small firms.

Rittenhouse Law opened in Center City last week, founded by attorneys Jeffrey Pustizzi, Catharine Sibel and Hunter Kintzing. Also joining them is paralegal Mary Warren.

Pustizzi, Sibel and Kintzing were lawyers at Spruce Law, a small firm that opened in 2010, founded by a former Cozen O'Connor lawyer. All three bring with them in-house and prior law firm experience as well.

Sibel started her career in-house with a real estate development group, O'Neill Properties Group, before joining Silverang, Donohoe, Rosenzweig & Haltzman, where she became a partner, and then Spruce Law. Kintzing was in-house at Susquehanna Bank before joining Spruce Law, and he also practiced at Duane Morris before that. Pustizzi, who is also a co-founder and general counsel of real estate investment company Alterra Property Group, also previously practiced at Spruce Law and at Stradley Ronon Stevens & Young.

The new boutique aims to work with developers, investors, family offices and privately held companies, assisting them with commercial real estate transactions.

Like Spruce Law, Rittenhouse is a spinoff not named after its partners, instead choosing the opulent Center City neighborhood as its namesake.

Sibel said she and her co-founders did not want their brand to be centered on a single person's name, so instead, they focused on "picking a name that had some historical significance to the Philadelphia landscape and real estate community."

At the new firm, she said, they plan to focus on serving a "strong and select group of clients" with a "deal-oriented" approach. That approach, she explained, "takes a lot of the fat out of legal fees that are maybe in some other settings have to be reflective of a big organization." She said that is easier to do well in a small firm.

With that in mind, the boutique isn't looking to grow dramatically anytime soon.

"For right now, our intent is to kind of stay where we are size-wise. We are always open to opportunities and we'll look to add a couple partners strategically over time," Sibel said.

Asked about the lawyers' departure, Spruce Law founder Jason Sieminski said in a statement Thursday: "At the heart of Spruce Law's core purpose is providing an innovative platform for lawyers to advance their career goals while serving the needs of their clients. The founders of Rittenhouse Law either met or came together as a team while working at Spruce Law. We wish the attorneys at Rittenhouse Law the best of luck in their new endeavor."

Other Moves by Pa.-Based Firms

Two locally based firms made significant additions outside of Pennsylvania this week.

Duane Morris added a partner in Chicago who will lead the firm's labor and employment practice there. Daniel Canales came from Ogletree, Deakins, Nash, Smoak & Stewart, where he was a shareholder.

Royer Cooper Cohen Braunfeld, based in Conshohocken, added two partners to its New York office and formed a new practice group focused on trademarks and brands.

Partner Donna Tobin will lead the new group. At her former firm, Frankfurt Kurnit Klein & Selz, she was co-chair of the trademark and brand management group. She was a partner at Baker & Hostetler before that. Her work has touched the food and beverages, furniture, textiles, fashion, consumer goods, pharmaceuticals, financial services, manufacturing, software and technology industries.

Partner Richard Siegal joined the corporate and business, private client services and tax practice groups. He came from Schiff Hardin, where he was a partner, and before that he was a partner at Kelley Drye & Warren and Cummins & Lockwood. But he began his career in Philadelphia, in the tax practice of now-defunct Wolf, Block, Schorr & Solis-Cohen.

Klehr Harrison Harvey Branzburg announced this month that Edward Kuna had joined its real estate and finance practice group as a partner. In making his move, he relocated to Philadelphia from Pittsburgh, where he practiced at Eckert Seamans Cherin & Mellott.

Ogletree, Frankfurt Kurnit, Schiff Hardin and Eckert Seamans did not respond to requests for comment Thursday.