MONACO (Reuters) - Mercedes bosses queued up to apologise to stunned Formula One world champion Lewis Hamilton on Sunday after an error that robbed him of victory at the showcase Monaco Grand Prix.

Hamilton had led from pole position until he was called in for fresh tyres when the safety car was deployed with 14 laps remaining.

They had calculated he would pit and retain the lead but instead cost Hamilton the race, halving his championship lead from 20 points to 10, while handing it to team mate Nico Rosberg instead. "It was a mistake by the team," said the team's non-executive chairman Niki Lauda, himself a three times world champion with plenty of experience of success and failure.

"Lewis said he was not happy with the tyres and they over-reacted completely wrong and called him in. There was no need, no reason. It was simply a mistake," added the Austrian. "They over-reacted 10 laps before the end, in Monaco. Where you can't pass anyway...we destroyed his race. I apologised already."

Mercedes motorsport head Toto Wolff said he too had immediately said sorry to Hamilton, who had not put a wheel wrong otherwise and was seemingly destined for a long-overdue second win in the principality.

"What the hell happened there? That's exactly the right question," he said. "The simple answer is we got the maths wrong. The calculation wrong. We thought we had a gap which we didn't have when the safety car came out."

Wolff refused to blame any one person, saying the team won and lost together, and denied flatly there had been any skulduggery to favour Rosberg in front of the German manufacturer's watching senior management.

"I went to see him now in the (media) scrum and...I apologised," he said. "That's probably the only thing you can do and he's a great leader, a great driver and I am sure that he will understand that sometimes we make errors. And this was such a situation."