Sources familiar with the two companies think a transaction could close within weeks.
In January, Axel Springer bought a minority stake in Business Insider, via a $25 million funding round that valued the company, founded by former Wall Street analyst Henry Blodget, at around $200 million. This new deal pegs Business Insider's value at around 500 million euros, sources say.
Last week, German Manager Magazin reported that Axel Springer was looking to buy a controlling stake in Business Insider. But people familiar with the transaction say that the plan is for a full acquisition. Blodget declined to comment, as did a rep for Axel Springer.
(Disclosure: If the Axel Springer/Business Insider deal goes through, it should be good news for me. I used to work for Blodget at Silicon Alley Insider, the predecessor to Business Insider, and I own shares in the company.)
Business Insider hasn't disclosed its revenues recently. In 2013, it did around $20 million. In January, when Blodget announced his latest funding round, he said revenues had grown 70 percent in 2014, and that the company was "solidly profitable" in the second half of the year.