Rosberg's lead cut to 1 point after penalty
NICO Rosberg had his Formula One world championship advantage over Mercedes team-mate Lewis Hamilton reduced to one point after the German was demoted from second to third place in the British Grand Prix on Sunday.
Race stewards imposed a 10-second penalty for receiving help from his team via radio transmissions, in breach of the regulations that state the driver must pilot the car alone and unaided.
Rosberg had finished the race, won by Hamilton for the third year in a row, 1.3sec ahead of Red Bull's Dutch teenager, Max Verstappen.
There are 11 rounds remaining. Rosberg reeled off four wins in a row at the start of the season while Hamilton has taken four of the last five.
Mercedes told Rosberg to avoid the seventh gear five laps from the end after he suffered problems, arguing after the race that the regulations allowed such advice if a terminal failure was imminent.
Team boss Toto Wolff read out part of the regulation on "driver aids", saying the list of permitted messages included "indication of a critical problem with the car".
Stewards said in their ruling that while the team "gave some instructions to the driver that were specifically permitted... the team then went further and gave instructions to the driver that were not permitted".
Mercedes said they intended to appeal the ruling, starting a process that could take weeks to resolve with a final decision made by the International Automobile Federation's court of appeal.
Hamilton can take the overall lead in the championship at the next race in Hungary on July 24.