Google Inc. has signed a lease for an entire 35-story tower that has started construction just east of the Central Library in downtown Austin, according to a commercial real estate source with knowledge of the deal.

Google declined to comment on the transaction, or on what it means for the company's plans for its Austin operations. As of this past August, Google had more than 800 employees in Austin.

Austin-area brokers and Greater Austin Chamber of Commerce officials say the lease deal would seem to signal a major commitment to the Austin market by Mountain View, Calif.-based Google, which is one of the world's largest companies.

“Google is a major player in our corporate community and an engaged community leader; we are pleased to see how they continue to grow," Charisse Bodisch, the chamber's senior vice president of economic development, said in emailed statement. "The expansions of our existing businesses reinforces commitment to our community and continues to indicate we have a vibrant economy.”

The new tower will rise at West Cesar Chavez and Nueces streets, on a tract known as Block 185. Trammel Crow is the developer of the building, which will have 790,000 square feet of space, enough to potentially house about 5,000 people, local commercial brokers say.

The building is scheduled to be ready for occupancy in the second quarter of 2022, according to a marketing brochure for the building circulated by commercial real estate services firm CBRE.

The location is part of the the former Thomas C. Green Water Treatment Plant, which Trammel Crow is redeveloping. Block 185 is the fourth and final parcel to be redeveloped. Google already occupies a 29-story high-rise, called 500 W. 2nd St., on one of the parcels. Other tracts are home to Northshore, an apartment tower with a tiered design, and the Austin Proper Hotel & Residences, which is nearing completion.

The marketing materials say the new tower will have a "premier lakefront location with unobstructed views" and a "skyline defining signature design" by Pelli Clarke Pelli Architects. STG Design is the local architecture firm that is working on the project. Both firms declined to comment.

Pelli Clarke Pelli, based in New Haven, Conn., has designed some of the world's most recognizable buildings, including the World Financial Center in New York, the International Finance Centre in Hong Kong, the Petronas Towers in Malaysia and Salesforce Tower, a 60-story office tower that is the tallest building in San Francisco.

CBRE's marketing brochure for the new building says it will have an expansive lobby with access to the nearby Second Street retail district; outdoor terraces on every level; a fitness center; recreation, lounge, kitchen and dining areas; conference centers; a bar/tavern; ground-floor retail and other amenities. The building also will have a plaza along Shoal Creek "where employees can enjoy an authentic Austin experience," the brochure states. There will be 1,327 parking spaces in total, both above and below ground.

MSD Capital, Michael Dell's personal investment firm, is a financial backer of the tower, the brochure says.

Trammell Crow closed on the purchase of Block 185 on Jan. 15, according to Greg Kiloh, the city's redevelopment project manager. The purchase price was about $10. 27 million, an amount negotiated and agreed to in the 2012 master development agreement between the city and Trammell Crow, Kiloh said.

In 2016, Gerardo Interiano, at the time Google's public affairs and government relations manager, confirmed the company's initial lease at 500 West 2nd St., where it has since expanded.

“Since 2007, hundreds of Googlers have lived and worked in Austin, enjoying all the city has to offer from our trails to our festivals, to countless breakfast tacos,” Interiano said in the September 2016 statement. “As a result of our recent growth, we are excited to share that Google Austin has signed a lease for over 200,000 square feet at the new Green Water Treatment Plant redevelopment at 500 West 2nd Street.”