BERLIN--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 also acquire the remaining 50% stake in