Commenting on his forthcoming move to France, Contepomi said: "This is one of the hardest decisions that I have ever had to make in my career. I spoke with my family about it at length, but I feel that the end of this season is the best time to make a new start.
"I have played some of the best years of my career with Leinster. They are the team that I have also played with the longest in my career.
"Since joining Leinster a few years ago I have seen the team grow, on and off the field, every year. I feel a strong link with Leinster because I have been blessed an Irish-born daughter (Catalina) and with people who supported my ambition to complete my medical studies.
"The supporters will always hold a special place in my heart for the way in which that they have treated me and my family.
"I would like to take this opportunity to thank the management, my team-mates and all of our supporters for the opportunity to play with a team that I will always hold close to my heart.
"We have three important months left in the season and my sole intention now is to do my best to try to help to win the Heineken Cup and retain the Magners League title for the club.
"It has been an incredible journey and I'd like to finish it on a high."
Commenting on the announcement, Leinster coach Michael Cheika said: "Felipe has been an unbelievable asset to the club and he's going to be sadly missed. He has been a great support for us at all levels and played an important role in the transition of the club into a strong professional organisation.
"His departure will inevitably provide an opportunity for another player, but Felipe still has a big role to play in the remaining months of the season."
Leinster Chief Executive Mick Dawson added: "Since joining Leinster in 2003, Felipe has been an outstanding ambassador for the province.
"He has been an integral part of the Leinster squad in both the Magners League and the Heineken Cup over the years and his level of performance has been unwavering in that time.
"A hugely popular and charismatic player amongst our loyal supporters as well as in the dressing room amongst his team-mates, I know how determined Felipe will be to finish this chapter of his career on a high.
"Whilst we did everything in our capacity to tempt Felipe to stay, he and his family will leave Leinster with our best wishes and thanks."