Kevin Pietersen has been fined for criticising Sky television commentator Nick Knight on
Pietersen was docked an undisclosed sum for comments aimed at the ex-England opener during the first Test against the West Indies at Lord's.
He wrote: "Can somebody please tell me how Knight has worked his way into the commentary box for Tests? Ridiculous."
The remarks were deemed "prejudicial to ECB interests and a breach of the England conditions of employment".
The England and Wales Cricket Board convened the hearing with managing director Hugh Morris and team director Andy Flower. Part of Pietersen's fine was suspended for 12 months.
England opener Alastair Cook, a non-tweeter, had earlier attempted to downplay the controversy, saying: "It always does get blown out of proportion, let's be honest.
Pietersen plays his county cricket for Surrey
"We always turn the volume down in the dressing room. I'm more worried about that red ball coming down at me than I am about what people are saying about it [on television]."
Pietersen has previously caused controversy on Twitter by using the social networking site to announce his
dropping from a one-day squad.
He said on Tuesday that, despite the furore, he would not stop using Twitter.
Left-handed batsman Knight played 17 Tests for England between 1995 and 2001, scoring 719 runs at an average of 23.96. He also hit 3,637 runs in 100 one-day internationals at 40.41.
In January, Sky agreed a new four-year deal to show live international and county cricket, believed to be worth at least £260m to the ECB.