Pique put pen to paper on a new five-year deal on Sunday and Bartomeu is delighted with the former Manchester United man's decision to continue his career at Camp Nou.
"It is very important to consolidate Gerard Pique at Barcelona," the Barca supremo is quoted as saying on the club's official website.
"He’s the best centre-back in the world and he is a core part of the new project here at Barcelona."
Sporting director Andoni Zubizarreta, meanwhile, was equally pleased by the 27-year-old's contract extension.
"Renewing Pique, our main centre-back, confirms the mutual confidence of the player and the club in the continuation and improvement of our project," the former Barca goalkeeper stated.
Pique has won four La Liga titles and two Champions League trophies since his return to Barcelona from United in 2008 but he is desperate to win more silverware under new coach and former Camp Nou favourite Luis Enrique.
"I hope we can enjoy as many successes as we have had already," the Spain international admitted.
"I am very excited. In his press conference Luis Enrique showed that he’s very clear about his ideas.
"He knows this place well and I think he’ll do a lot of good for us. I am really looking forward to working under him.
"Barcelona have to be at the top, winning titles and feeling important among the elite of European and world football. We have a team, and a coach. We have all the ingredients to get back where we belong."