SAN JOSE — Google is in talks to create a massive tech campus in the heart of downtown San Jose’s Diridon Station area that could accommodate up to 20,000 jobs and transform the area into a transit-oriented tech village, city officials said Tuesday.

Google and the city are discussing a potential mixed-used development that could include more than 6 million square feet of office and research-and-development space, potentially making it the company’s largest collection of tech offices. It would be larger than the search giant’s roughly 3.1-million-square-foot Mountain View headquarters, known as the Googleplex, which currently is its biggest U.S. work hub. The largest single building occupied by Google is a company-owned office tower, a 2.9-million-square-foot art deco skyscraper in Manhattan.

Google ultimately intends to buy all the parcels in a roughly 240-acre area that would be needed for the mega-campus, said a person familiar with the matter.

Google’s expansion plans could dovetail with San Jose’s own quest to maximize transit links in and out of Diridon Station. The area is deemed attractive for offices, homes and retail because it’s a hub for Amtrak, Caltrain and a light-rail system. It’s also slated for a BART station and a possible high-speed rail line connection, although those won’t materialize for years. All the transit upgrades could increase the number of commuters to downtown San Jose by eight-fold.

“Based on our conversations with Google, we share a collective vision for the future of this space, a vision of urban design that will invite the public into the station,” San Jose Mayor Sam Liccardo said during an event near the train station to announce the development plans.

Google didn’t immediately respond to a request for comment about its plans.

“We will transform this collection of industrial parcels, bars, and parking lots into a dynamic, vibrant epicenter of technology and creativity, complete with public plazas, retail, restaurants, world-class architecture, and of course, brilliant minds of one of the planet’s most innovative companies,” the mayor said, referring to Google.

The city also envisions a different kind of tech campus than many of those already dotting the valley.

“In partnership with Google, we can re-imagine Silicon Valley’s landscape by creating a vibrant, architecturally iconic, transit-focused village that provides a model for a more sustainable future, and a sharp departure from the sprawling, auto-oriented tilt-up tech campuses of the valley’s past,” Liccardo said.

Mountain View-based Google, owned by a tech conglomerate called Alphabet, has been on an expansion march throughout the Bay Area through an array of leases and purchases. Mountain View, Palo Alto, Redwood City, Sunnyvale and north San Jose are among the locations where Google has planted its flag.

Google’s venture into downtown San Jose would re-sculpt the Diridon Station area’s motley collection of properties along and near Autumn and Montgomery streets a short distance from the SAP Center. The area was once proposed for a baseball stadium and is now targeted for an 8.3-acre, mixed-use office, retail and residential complex planned by developer Trammell Crow.

“Google’s interest in potentially laying down roots in San Jose will be transformational to the landscape of downtown and the entire city,” Vice Mayor Magdalena Carrasco said.

Google’s plans for downtown San Jose have emerged as two groups of property investors have quietly launched a shopping spree for properties in the Diridon Station area, a land assembly that could eventually accommodate one or more mega-campuses for tech workers, along with housing and stores. The two groups of buyers have spent a combined $124 million in the acquisition binge.

San Jose council members expressed optimism about Google’s potential entry to downtown.

“It is the best use for Diridon,” San Jose Councilman Raul Peralez said. “We share the company’s vision and look forward to working with them.”

City staffers intend to propose that San Jose enter into exclusive negotiations with Google to enable the search giant to collect properties owned by the city and the San Jose Redevelopment Agency’s successor.

“We look forward to working with Google and stakeholders to bring forward a transformative project,” said Kim Walesh, San Jose’s economic development director.

The City Council is slated to consider the staff proposal on June 20.

Some business owners expressed misgivings about the prospect of being Google’s neighbor — or being displaced by the digital giant.

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“Looks like Google is buying up everything they can around here,” said Edgar Salcedo, owner of Ed’s Scientific Auto Body on South Autumn Street.

Still, city officials believe San Jose is now on the path of progress.

“Silicon Valley’s center of gravity is shifting southward,” Liccardo said. “As we build Diridon to become the busiest multi-modal station in the West, the tens of thousands who will commute here daily will know that they have arrived in Silicon Valley’s urban center, and that downtown San Jose has arrived.”