PORTLAND, Ore. - Daimler Trucks North America announced Friday it will expand its Portland headquarters after state and city officials offered nearly $20 million in incentives.

The unit of Daimler AG said its new building will house 400 new white-collar workers and hundreds of existing employees who now work in rented offices across the Willamette River. The expansion will happen on the company’s existing campus on Swan Island.

Daimler makes heavy-duty trucks and school buses under brands that include Freightliner, Western Star and Thomas Built. The German company employs about 2,800 people at its North American headquarters in Portland, including about 750 people in blue-collar manufacturing jobs.

Daimler has large operations in North and South Carolina and had considered expanding there.

Explaining the decision to stay in Portland, Daimler Trucks North America CEO Martin Daum cited the city’s quality of life, the company’s exist ing workforce and its history. Freightliner Corp. was founded in Portland in the 1940s before being acquired by Daimler.

“I think the city and the history creates a little bit of culture and the soul of a company, and you can’t rip the soul out,” Daum said at a news conference. “You might get lost afterward.”

Daum said the new building should suit the company for at least the next 20 years.

The company will get about $4 million from economic development accounts managed by the state of Oregon and about $15 million from the city of Portland. The incentives include forgivable loans and property tax abatements, some of which are tied to company promises to maintain its existing jobs or create new ones.

Daimler’s decision to expand in Portland will protect not just its white-collar headquarters jobs but the manufacturing positions as well, said Oregon Gov. John Kitzhaber, a Democrat.

“I’m very, very proud that Oregon continues to be one of the best places for advanced manufacturing in the country,” Kitzhaber said.

Portland Mayor Charlie Hales also praised the company’s decision and touted the advantages of manufacturing jobs.

“It’s great that we make software, we make apps and we make movies here,” Hales said. “But I love it especially that we make real things and sell them to the world.”

The company said it will donate money to local schools to support science, technology, engineering and math education along with internship programs to encourage young people to pursue manufacturing jobs when they graduate from high school.