BERLIN (AP) — Germany publishing company Axel Springer said Thursday that it has signed a deal to buy the U.S.-based political news company Politico and the tech news site Protocol from founder Robert L. Allbritton for an undisclosed sum.

Axel Springer said the purchase will increase the publisher's reach in the United States, where it already owns online media company Insider and the business-oriented Morning Brew. Under the deal, the German publisher will acquire the remaining 50% stake in Politico Europe it didn't already own.

Axel Springer chief executive Mathias Doepfner said Politico's staff had “disrupted digital political journalism and set new standards.”

“Objective quality journalism is more important than ever, and we mutually believe in the necessity of editorial independence and nonpartisan reporting,” Doepfner said in a statement. "This is crucial for our future success and accelerated growth.”

Allbritton, who founded Politico in 2007, called the site “without a doubt the most impressive and most enduring of the many experiments in new publications over the past generation.”

“Particularly in recent years, we have put the emphasis on doing rather than boasting, and what multiple competitors have aspired to—a consistently profitable publication that supports true journalistic excellence—we have achieved,” he said in the joint statement.

Allbritton will continue as publisher of Politico and Protocol, according to the statement, while the editorial and management leadership teams of both sites will remain in place and continue to operate separately from Axel Springer’s other U.S. brands.