Max Mosley and Bernie Ecclestone have ended the bitter feuding that threatened to tear apart Formula One and will now work together on a radical overhaul of the sport.

The two friends have attacked each other for weeks in the wake of Mosley's refusal to resign as president of the FIA, the sport's governing body, after revelations about his private life.

But the first evidence of a reconciliation came as Ecclestone endorsed Mosley's blueprint for a new F1 agenda. "The bottom line is simple, we have moved to patch up our differences," said Ecclestone following Mosley's letter to F1 team chiefs in which claimed the sport has become so expensive as to be unsustainable.

He wrote: "The major manufacturers are employing up to 1,000 people to put two cars on the grid. This is clearly unacceptable at a time when these companies are facing difficult market conditions."

He has asked the teams to write a new set of technical regulations, to come into force from 2011, that will eventually cut operating budgets by 50 per cent, while also maintaining top speeds and making overtaking easier.

If a majority fail to agree on a new format, the FIA will do it for them.

Ecclestone welcomed an initiative, which previously he might have seen as encroaching on his territory.

He said: "I am happy the FIA are allowing the teams to write the regulations. What Max put in the letter is correct; it's a little cranky that it takes 1,000 people to put two cars on the grid."