Kevin Pietersen was fined on Monday following his online outburst after being dropped by England for the first time in his career.
"He has been fined an undisclosed sum in accordance with the terms and conditions of his England Central Contract," the England and Wales Cricket Board (ECB) said in a statement.
The 30-year-old batsman posted a Twitter message last Tuesday announcing that he had been dropped for the one-day series at home to Pakistan. The message contained an expletive.
Pietersen's punishment was decided after an ECB disciplinary hearing at Lord's convened by Hugh Morris, Managing Director of England Cricket and England team director Andy Flower.
"The hearing considered two charges against Kevin Pietersen relating to recent comments made on Twitter following his omission from England's one-day squad for the series against Pakistan," the statement said.
"Pietersen pleaded guilty to both charges and offered an unreserved apology to ECB and the England team management for his actions."
The former England captain apologised publicly last Wednesday, insisting on Surrey TV that his comments "had not been for the public domain".
The ECB said Pietersen had been dropped so that he could regain some form with county side Surrey after a run of disappointing scores.
