Meister Seelig & Fein, a 60-attorney firm, has added three attorneys from Ostrow Kaufman, a now-closed intellectual property boutique.

Seth Ostrow and Antonio Papageorgiou, two of the boutique’s three partners, started Monday at Meister Seelig as partners. An associate, George Zalepa, is joining them.

At Meister Seelig, the firm said, Ostrow and Papageorgiou’s patent litigation and prosecution practices will continue to focus on software, telecommunications and networks. The firm now has about 10 attorneys in its IP practice. Meister Seelig also focuses on litigation, real estate, corporate and employment law.

Managing partner Mark Seelig said his firm is interviewing more attorneys in anticipation of the firm’s July move to a new office with 59,000 square feet at 125 Park Ave. The firm is currently headquartered at 140 East 45th St., with 36,000 square feet. Seelig said the firm may hire 10 attorneys within the first year of moving into the new office.

Ostrow-Kaufman, a five-attorney firm founded in 2008, ceased operations last month, Ostrow said. The firm’s other name partner, Matthew Kaufman, could not be reached for comment.

Ostrow said running a boutique with limited staff was challenging while handling large litigations, and the boutique often collaborated with other firms, including Meister Seelig, on patent litigation. He said his firm needed additional personnel on large matters, but “as a small boutique, litigation comes and goes in surges.”

“I realized we would all be better off” if our attorneys joined Meister Seelig, Ostrow said, noting he was impressed with Meister Seelig’s talent and expertise.