The contest for control of central and eastern Europe's exchanges has escalated, with two of the biggest western stock market operators confirming they were eyeing acquisitions in the region, just hours after the Ljubljana Stock Exchange rejected advances by a third.

Shareholders in the Slovenian exchange revealed yesterday voted to block its sale to OMX, the acquisitive Nordic and Baltic exchange operator, which bid for the exchange on December 14, claiming that ownership by OMX would enhance the efficiency, liquidity and visibility of the Slovenian capital market.