On 19 April 2000 we signed an agreement with Gas Natural to work together on using natural gas in the public-transport system of Barcelona and the metropolitan area. The first objective of the agreement is to establish the actions needed to initially replace 50% of the standard buses over the 2000-2001 period with natural gas-powered vehicles. The programme will gradually be increased according to availability and technological advances until a total of 250 vehicles run on this fuel source.