Lewis Hamilton's exit from McLaren was instigated by his representatives, Mercedes' Ross Brawn has revealed.
Hamilton, 27, announced on Friday that he has signed a three-year deal with Mercedes to replace Michael Schumacher from next season.
"Lewis's management expressed interest, wanted to know what our plans were and it grew from there," said Brawn.
"Everyone knew Lewis's contract was coming to an end this year, so things really developed from that point."
Mercedes' team principal added: "Once we were able to explain what we were trying to achieve here, what our ambitions were and the things we were putting in place, I think it was the type of thing Lewis needed, or wanted, at this stage of his career."
However, Brawn denied Hamilton had been promised, or had demanded, priority over new team-mate Nico Rosberg as part of the deal negotiated by Hamilton's management company XIX.
Hamilton currently sits fourth in the drivers' title standings on 142 points, 49 ahead of 27-year-old German Rosberg, who is seventh.
"There isn't a number one status," he said. "To be clear, Lewis never mentioned that in all the discussions we had with him.
"He wanted to make sure that he had parity, that there was equality in what was done, but he never ever asked for number one status.
"We wouldn't be keen to give that to a driver because it tends to say you're not looking after the other driver as well as you should."
Hamilton's arrival has left seven-time world champion Schumacher, 43, considering whether to retire from the sport or find a new drive for the 2013 season.
But Brawn insists Schumacher was not forced out to accommodate Hamilton, adding the German had never indicated he wanted to stay.
"We never got to that stage in the sense Michael was always uncertain what he wanted to do," he added.
"As things moved along [with Hamilton] and these things started happening in parallel, Michael's uncertainty and growing interest from Lewis in what the team had to offer, one effectively overtook the other.
"Michael was always aware of all the discussions we were having. He is delighted the team has managed to secure such a strong option for the future."
Meanwhile, McLaren team principal Martin Whitmarsh is confident Hamilton's impending departure will not distract the Woking-based outfit from their twin goal of winning both the drivers' and constructors' world championships.
"In the short-term we've got six grands prix ahead of us which we can win," said Whitmarsh.
"It's acknowledged we have got the quickest car in Formula 1, so we're going to try and win these six races and work towards winning two world championships. That's very much our short term focus.
"We will be working together. Lewis has assured me, at the moment he is a McLaren driver, he is focused on winning and is a professional. The team will be professional around him and we will do the best we can."