The traditional way to insure against losing an auction for a juicy asset is to buy a big stake in the target business. If you win the auction, the stake lowers your average purchase price. Lose, and you make a profit on selling it to the successful bidder.

EDF, the French energy group vying with Germany's RWE to buy British Energy, has taken this concept and added a cunning twist. It has bought up land round British Energy's reactors - land that whoever wins the auction for the energy group would want to develop to build more capacity.