The London Stock Exchange and Nasdaq OMX became unlikely bedfellows this morning when it was announced that the US operator would take a 5% stake – and a board seat – in LCH.Clearnet, the international clearinghouse which the LSE is to acquire in a landmark €351m transaction.

The LSE today agreed revised terms to pay €15 per share to increase its stake in LCH.Clearnet from 2.3% to 57.8%. The deal involves Nasdaq OMX increasing its share in the clearinghouse from 3.7% to 5%, with Bob Greifeld, its chief executive, set to join the LCH board.