A year ago, there was extensive talk of converting Boston’s 40 Broad St. to a residential or hotel use, but as evidenced by new owner Transwestern Investment Co.’s lease to a local law firm, the building now seems destined to remain an office address.

Wilmer Cutler Pickering Hale and Dorr, aka WilmerHale, has agreed to lease nearly 25,000 square feet at the 11-story, 291,000-square-foot building, which is located in the heart of the city’s Financial District and close to such major attractions as Faneuil Hall Marketplace and the New England Aquarium. According to WilmerHale partner Joel Sirkin, the space is needed for large-scale litigation matters.

The lease at 40 Broad St. “is an excellent way for us to expand case-room needs close to our 60 State St. offices in a competitive real estate market,” said Sirkin, referring to the firm’s local headquarters a few blocks away. Including a practice in Waltham, WilmerHale has more than 1,000 attorneys and offices throughout the United States and globally in such markets as Brussels, Belgium; Munich, Germany; Beijing, China; and London.

“We are thrilled to add a firm of WilmerHale’s stature to our tenant roster at 40 Broad St.,” said Transwestern Senior Vice President Joseph Concepcion. The pact, he said, is the first in what Transwestern hopes will be a series of commitments to quickly refill 40 Broad St. Besides migration of tenants on their own volition, the building was substantially emptied out during the past two years by former owner Prudential Real Estate Investors in order to make the asset marketable for a residential or alternative use, but Transwestern’s view that the Hub office market was recovering enough to lure tenants back to the property appears to be paying off as the leasing program kicks into gear.

“We’re very excited about it,” Jones Lang LaSalle Senior Vice President William F. Collins said last week of the WilmerHale deal, particularly given an encouraging level of interest in the property. Collins, who represented WilmerHale in the inaugural lease along with JLL Managing Director William Barrack, estimated that the building has seen about 1 million square feet of requirements visiting the building this summer, while there is approximately 600,000 square feet of proposals currently being considered. JLL Senior Vice President Brad McGill represented Transwestern in the WilmerHale negotiatons.

Now that the first agreement has been cemented, JLL is seeking to continue the momentum, and to date, the activity has been “unbelievable,” said Collins, adding that Transwestern is currently entertaining prospects needing a full floor (25,000 square feet) up to those who would take the entire 250,000 square feet still available. “So far, so good,” Collins said of tenant response to 40 Broad St., which Transwestern acquired earlier this year for $50 million.