IRF made a binding agreement to buy shares from two major Proton shareholders at 9.50 euros apiece to become a "strategic investor," Proton said Thursday in a regulatory filing. This gives the deal a value of as much 129 million euros ($165 million), IRF said in a London Stock Exchange filing.

IRF invests in financial services companies, credit institutions and insurance companies in Greece, Bulgaria, Romania and Turkey, whose economies have been growing faster than the European Union.

Athens-based Proton focuses on investment banking, was listed on the Athens Stock Exchange in December and plans to merge with Omega Bank SA, another Greek lender that focuses on lending to households and small businesses.

The deal, expected to be completed in four to six weeks, is subject to approval by IRF's shareholders.