Last year was a watershed 12 months in crossborder merger control, as competition authorities in the US and Europe attempted to learn from past mistakes and become more user-friendly, according to a new report by White & Case, the US law firm.

Mark Gidley, partner in the global competition group at White & Case in Washington and co-editor of its new report, said: "In the debris of the GE-Honeywell crack up, we're seeing merger control regimes begin to come of age with efforts by authorities to streamline and co-ordinate filing requirements and procedures." GE's merger with Honeywell was controversially blocked by the European Commission in 2001 having been passed in the US.