Clark Foundation's BernardoTapia Garcia guides a steel beam while working on the City CenterDC complex in April 2011 in Washington. (Matt McClain/The Washington Post)

Covington & Burling, one of the District’s largest and most prestigious law firms, has signed a letter of intent to move its global headquarters from Pennsylvania Avenue to CityCenter DC, developers of the $950 million project confirmed Wednesday.

Covington has more than 500 lawyers in Washington and has been looking for 450,000 square feet, making it one of the largest and most valuable leases in the region. The developers of City-Center, including Hines, Archstone and the sovereign wealth fund of Qatar, were competing with other developers for the lease.

William B. Alsup III, senior vice president at Hines, confirmed that Covington had signed a letter of intent to move into the project’s offices.

Rebecca Carr, a Covington spokeswoman, said that the total square footage is 415,000 and that the firm plans to move in 2014.

The firm issued a statement in February saying that although it was happy with its offices at 1201 and 1275 Pennsylvania Ave. NW, “the neighborhood around us has evolved in dynamic ways, and there are some interesting new developments and upcoming opportunities in the property market in the Penn Quarter and East End.”

The relocation of a major law firm off Pennsylvania Avenue to the CityCenter site, located on the footprint of the city’s former convention center between Ninth and 11th streets NW, would further solidify the eastern end of downtown as a hot destination for employers. Living Social has multiple offices in the area, and the American Association of Medical Colleges is building new headquarters on the 600 block of K Street NW.

Construction at CityCenter is running about one month ahead of schedule. It is six stories above grade, with completion scheduled for July 2013. The developers previously nearly landed another law firm for the space, Skadden, Arps, Slate, Meagher & Flom, before those negotiations fell through. It had also discussed the space with the law firm Arnold & Porter.