He was speaking at a reception in the British Embassy in Paris hosted by the Ambassador Sir Peter Westmacott hours before the France v Wales international.
The reception was also attended by former Welsh rugby stars such as Jonathan Davies, Derwyn Jones and Gwyn Jones and the Welsh-born wife of the French Prime Minister, Penelope Fillon.
Dennis Gethin said: "I firmly believe that after 130 years of history of the WRU that at long last we are now looking not just at the rugby but at the role rugby plays in helping Welsh businesses punch above their weight around the world.
"This gathering tonight has proved a marvellous opportunity to show leading business people how much rugby means to our nation and to the world.
"Rugby is the fabric of our society and therefore the WRU will be looking to invest more in the grassroots of the game in the years ahead."
First Minister Rhodri Morgan said: "Tonight we can celebrate the link between Wales and France which is getting ever closer with the help of rugby. This meeting is a great occasion for celebrating that link and making it work."