Withdrawn mergers and acquisitions in Europe have hit the highest levels for six years, compounded by the high-profile collapse of a multi-billion euro deal last week.

The number of failed bids stormed to $243.3bn (€185.8bn) this year, more than double the previous high of $109.6bn in 2000, according to Thomson Financial, an investment banking data provider. The value of withdrawn deals, worth 13% of the total value of bids announced in Europe, is almost five times higher than last year. In 2000, failed deals were worth 6% of those announced. This year's total follows the collapse of the €20.6bn ($27bn) bid by Spain's Abertis for Autostrade, the Italian toll road operator, last week. It was the third-largest deal to be withdrawn this year. The companies released a joint statement, blaming regulatory hurdles which made the deal "impossible" in its present form. Political opposition could derail a further €70bn worth of deals announced this year. German utility E.On is some way off completing its €37.1bn takeover of power group Endesa despite first bidding in February. The Spanish government imposed conditions on the deal, which were criticised by the European Commission as illegal, before domestic construction company Acciona started building a blocking stake. The average size of each withdrawn deal has risen this year to $2.5bn from $500m in 2000, Thomson said. The largest bid to fail this year was the $29.3bn offer from a consortium led by Goldman Sachs for airports operator BAA, which was abandoned in June. It paved the way for construction group Ferrovial to buy the airport group. The second-largest European bid to fail this year was tabled by Aviva, a UK insurer. It bid $28.5bn for Prudential in March, but withdrew when its smaller rival refused to co-operate.