Transport Minister Doris Leuthard joined French President Nicolas Sarkozy for the inauguration on Thursday of the new eastern high speed Rhine/Rhône rail line.
The Swiss government contributed some SFr100 million (€82 million) to the construction of the rail line which is expected to reduce travel time between Zurich/Basel and Paris by 30 minutes when it opens in December.
The 140-kilometre rail link runs between Mulhouse on the Swiss, French and German border, and Dijon in eastern France.
The Swiss contribution to the estimated €2.3 billion total cost was approved by Swiss voters and is part of a programme to improve transport links between Switzerland and France and southern Germany.
The inauguration ceremony was held at the new high-speed train station of Belfort-Meroux in France.