Nordic and Baltic market operator OMX has suspended trading in its shares on its own Stockholm exchange amid rising speculation of a bid for the Sweden-based firm from the London Stock Exchange (LSE) or Nasdaq.
OMX is due to release further information about the share suspension before markets open on Friday morning. The shares had risen 3.2% on the day to SKr180 before trading was halted. The stock has risen 14% in the past week and is up 43% so far this year on the back of bid talk.
OMX said in April that it was in "cooperation talks" with other exchanges, which were not disclosed. That statement followed press reports that Nasdaq had made a Skr23 billion offer for the company. But recent market speculation has pitched the LSE as a potential bidder for OMX, as well as Germany's Deutsche Börse.
The exchange operator has refused to comment on any speculation. OMX CEO Magnus Böcker unexpectedly failed to show for a panel session at an industry event in London today. Another notable absentee was LSE chief executive Clara Furse who was scheduled to attend the event but pulled out earlier.
The Scandinavian market operator has previously been the subject of bid talk from a number of potential buyers, including Nasdaq and the LSE. OMX also tried to buy the UK exchange and originally launched a hostile takeover in 2000, which was rejected by LSE shareholders.
However, a more mundane explanation for the suspension of trading may relate to recently disclosed plans by the Swedish government to sell its 6.7% stake in OMX as part of a national privatisation programme.