Analysts at Jefferies said: "Investors may be a little surprised that Centrica's management are making a near £200 million acquisition in current market conditions, particularly given their overriding need to convince investors of their capital discipline.”
Neas Energy has around 250 employees, who manage and trade energy on behalf of clients that own power stations in more than 20 countries.
This expansion comes as Centrica has been hit hard by weak energy prices and fierce competition in its home market.