A UAE company controlled by the country's national security adviser has bought a 50% stake in a Turkish company with ties to President Recep Tayyip Erdogan, in the first major deal between the countries since the thaw in relations.

A division of International Holding Co. in Abu Dhabi acquired a stake in renewable energy company Kalyon Enerji Yatirimlari AS for AED1.8 billion ($490 million). IHC is the UAE's most valuable listed company and is controlled by the Royal Group, a conglomerate of which Sheikh Tahnoun bin Zayed Al Nahyan, the UAE's national security adviser and brother of the president, is chairman.

The Emirati company's expansion in Turkey could pave the way for a string of deals between the two countries as wealth funds in the UAE's oil-rich capital seek targets for billions of dollars of investment. The deal is also another sign of a turning point in relations between the two countries, which have been at loggerheads over a range of issues for much of the past decade.