The former Liverpool man's current deal runs until 2014 but he is keen to extend his stay in the Catalan capital.
He told Mundo Deportivo, "(The new deal) is on the right track and I hope it will be closed shortly. I am happy, I feel valued and I want to continue for many years.
"Signing for Barca was the best decision of my life. I have won people's confidence and now I want to maintain it."
The Argentina international also hinted that his future lies at the back rather than the holding midfield role he deployed in England and previously in his homeland.
"In this club I feel more comfortable playing as a central defender than a midfielder but I will play where I am asked."
Mascherano, meanwhile, backed his compatriot and team-mate Lionel Messi to retain the Balon d'Or as the world's best player later this year.
"As regards the Balon d'Or, it is a personal decision, a question of preferences, but I would vote for Messi followed by Xavi and Andres Iniesta. For me titles count but they are up against a kid that has scored more than 80 goals this season."