The National Parks Service selected a California contractor Wednesday to repair the Washington Monument, which sustained extensive damage last year when a 5.8-magnitude earthquake struck the region.

Tutor Perini Management Services Group won a $9.6 million contract to repair the marble and granite landmark. The company previously worked on the Ronald Reagan Building, the largest federal building in the District, officials said.

The contractor will be joined by Maryland-based Grunley Construction, Virginia’s Lorton Stone and Universal Builder’s Supply of New York. All three companies were involved in the 1998 Washington Monument restoration.

Money for the repairs came from a $7.5 million donation from philanthropist David Rubenstein that matched government funding from the National Mall and Park Services’ trust fund.

Officials estimate the total project cost at $15 million, including already completed elevator repairs and a seismic evaluation, which began soon after the earthquake last summer.

Two months of pre-construction work is expected to take place before workers can begin putting scaffolding over the monument, officials said.

The scaffolding will be similar to the one that surrounded the monument during its previous restoration. Then, architect Michael Graves created a design that surrounded the monument instead of being attached to it. It included 37 miles of aluminum tubing and contained modules that, when combined, could hold up to 1 million pounds.

Officials said that this time, it will take four to six months to create the scaffolding surrounding the 555-foot, 90-ton monument.

After the scaffolding is completed, workers will begin removing loose stone fragments from the interior and exterior, securing cracked stones and high beams, removing, repairing and reinstalling cracked glass panels, as well as performing a low-pressure wash of the monument’s exterior.

Officials declined to say when the repairs might be completed, citing weather, construction delays and the January presidential inauguration as factors that could effect the work.

Earlier, National Park Service officials estimated that the monument could be closed until 2014. Despite that, they say they are working hard to reopen it to the public; nearly 800,000 people visit the monument each year.

“I know visitors have been disappointed that the monument has been closed for what seems like a long time, but I want to assure them that we’re doing everything we can to get this iconic landmark reopened as soon as possible, and we’re not wasting any time,” said Bob Vogel, superintendent of the Park Service’s Mall and memorial parks.