The 32-year-old was added to the Test tour for England's contest against India, despite originally being snubbed following an alleged falling-out with his teammates and the England and Wales Cricket Board.
Pietersen tweeted: "BOOOOOOOOM!! The happiest days of my career have been playing cricket for ENG.. Long may that continue! Thanks everyone for your kind words."
Pietersen was likely to return to the England squad after the ECB confirmed that the batsman would be re-integrated into the side.