Nico Rosberg announced his retirement from Formula One on Friday, just five days after winning the world title for Mercedes in a move that stunned motor racing.

"I took my decision on Monday evening. After reflecting for a day," the German said in a statement on his Facebook page which said he wanted to devote more time to his family.

"The only thing that makes this decision in any way difficult for me is because I am putting my racing family into a tough situation."