SUNNYVALE — After the purchase of a South Bay office campus called Mathilda Commons for $350 million, Apple has spent well over a half-billion dollars on Santa Clara County real estate in just a matter of days.

According to documents filed on June 26 with the Santa Clara County Recorder’s Office, the 382,500-square-foot two-building campus is at 615 and 625 North Mathilda Ave. in Sunnyvale.

The $350 million that Apple paid was 19.5% above the assessed value of $292.8 million for the campus as of January 2024. The price appears to be the most paid for a property in Santa Clara County this year.

The recent purchase and other South Bay property acquisitions and leases have bolstered Apple’s efforts to strengthen the company’s decades-long presence in the region.“The Santa Clara Valley has been home to Apple for more than 40 years, and we’re proud to continue investing in world-class facilities for our teams here,” said Kristina Raspe, Apple’s vice president of Global Real Estate and Facilities.

In addition to the Sunnyvale purchase, Apple paid just over $166.9 million to buy a three-building office campus at 10200 North Tantau Ave. in Cupertino in a deal that closed on June 24, county documents show.

In both transactions, Apple was leasing the two office hubs from real estate firms that wound up selling the properties.

Bay Area real estate firm Jay Paul Co. had leased the Sunnyvale campus to Apple in 2022. The campus could provide enough space for 1,500 to 1,900 workers.

In recent years, Apple bought other office properties that it had been leasing in Cupertino.

In 2021, the company paid $450 million for a five-building office complex along North De Anza Boulevard, Mariani Avenue and Valley Green Drive near Interstate 280.

In 2023, Apple acquired a 10-building campus known as Apple Results Way. The company and the seller kept the price secret.

Also in 2023, Apple paid $70 million for an office building at 10200 North De Anza Blvd. The deal represented a 35% decline in the building’s value.

In at least one instance, Apple was a seller of a South Bay office building. It sold a north San Jose building to Samsung for $27 million in February.