The International Automobile Federation (FIA) on Friday reprimanded the Mercedes Formula One race team and tyre-makers Pirelli for carrying out unauthorised tyre tests.
The tests, carried out over three days in May in Barcelona, followed protests from the Red Bull and Ferrari teams that they contravened Formula One race laws.
The much-anticipated decision followed a day of hearings in Paris on Thursday, held by the FIA's international tribunal, at which both Mercedes and Pirelli defended their actions, saying they had no intention of disobeying the sport's regulations.
The issue has badly divided Formula One with Mercedes on one side and world championship rivals Red Bull and Ferrari on the other, and the FIA had a range of sanctions at its disposal, including fines and suspensions.
But in what will be seen in some quarters as a let-off for both companies, the sport's ruling body settled for simple reprimands, with Mercedes also suspended from participating in a forthcoming three-day young driver training test to be held at Silverstone on July 17-19.
The tests were carried out by Mercedes drivers Lewis Hamilton and Nico Rosberg but under FIA rules such testing of tyres during the season, using the latest Formula One team cars, were banned.
Red Bull and Ferrari, sworn rivals of Mercedes for this years drivers' and constructors' championships, promptly lodged protests, claiming that the German team had been seeking to gain an unfair advantage and that Pirelli had been complicit.
Mercedes claimed they were had done nothing wrong as the tests had been wholly organised and carried out by Pirelli, controlling the running of the car and the driver for the duration of the test.
Pirelli had reportedly been considering suing the FIA if the company was hit with a heavy penalty.
The issuing of simple reprimands had been proposed by Mercedes' lawyer Paul Harris at the end of Thursday's sessions.
In its ruling the FIA said: "The FIA wishes that lessons are learnt from this case and from the decision handed down.
"To this end, the FIA will make sure, in association with all F1 teams, that its control of the testings is strengthened."