"Suitable disciplinary measures have been taken for the incident," the media statement announced.
But despite warning earlier that the era of 'free racing' may now be over, Mercedes said on Friday it "remains committed to hard, fair racing because this is the right way to win world championships".
"It has been made clear that another such incident will not be tolerated," the statement added. "But Nico and Lewis are our drivers and we believe in them.
"They remain free to race" for the world championship, Mercedes said.
Shortly after the Mercedes statement, Rosberg posted his own statement on Facebook.
It said he has spent "a lot of time thinking" about the Spa incident since Sunday.
"I have already expressed my regret about the incident but, after meeting with Toto, Paddy and Lewis today, I wish to go a step further and describe it as an error of judgement on my part," said Rosberg.
"For that error of judgement, I apologise to Lewis and the team. I also want to say sorry to the fans who were deprived of our battle for the lead in Belgium.
"As drivers, we have a clear responsibility to the team, the fans of the sport, our partners and Mercedes-Benz to deliver clean racing.
"I look forward to concluding the season with hard, fair competition on and off track right up to the final lap of the season in Abu Dhabi," added Rosberg.