Japan's NTT Communications Corp said it has agreed to buy German data centre firm e-shelter, becoming Europe's third biggest operator in the sector, in the latest in a series of overseas acquisitions to counter sluggish growth at home.

NTT Communications, an unlisted division of Japanese telecom firm Nippon Telegraph and Telephone Corp (NTT) didn't disclose the deal's financial terms. A person familiar with the matter told Reuters earlier this month the NTT unit was in talks to buy e-shelter for about 100 billion yen ($832 million).

In a joint statement, NTT Communications and e-shelter said the Japanese firm will acquire 86.7 percent of the German company, founded in 2000. Operating data centres in four major cities in Germany including Berlin, as well as in Zurich and Vienna, e-shelter is Germany's biggest provider of data centre services, they said.

The European deal stretches the NTT brand further across the globe. In 2010, parent NTT bought South Africa's Dimension Data for 382 billion yen, while in 2013 NTT Communications signed deals with a combined value of 85.5 billion yen to take over two U.S. cloud computing firms, Virtela Technology Services and RagingWire Data Centers.