The 21-year-old has received a significant increase in salary but the length of the contract has not been extended while the minimum release fee clause remains the same of 90million Euros.
"This is the price for the excellent two seasons that the kid is developing at the club," Mata's father and agent Juan Manuel said.
"We are satisfied after the last meetings."
Sporting director Fernando Gomez was quick to play down any notion that Mata would soon be leaving the Mestalla.
"We have not received any formal propositions. I do not say that will be the same in the future," he said.