Consob, the Italian financial regulator, today forced Banca Popolare di Lodi to launch a full takeover for larger domestic rival Antonveneta after discovering it had built an undisclosed stake of more than 30%. Pop Lodi immediately sought to reverse Consob's ruling.

Antonveneta is already subject to a €6.3bn ($8.1bn) bid from the Netherlands bank ABN Amro which complained to the regulator claiming Pop Lodi had been acting in concert with other shareholders to build a substantial stake.