Formula One's commercial supremo Bernie Ecclestone says he has been asked to stay on for three years after an imminent takeover of the sport is completed by U.S. cable TV mogul John Malone's Liberty Media.

"They want me to be here for three years," the 85-year-old, who over the decades has built the sport into a business with annual turnover of around $1.9 billion, told Reuters on Wednesday.

Media reports have suggested the first part of a broader deal between outgoing rights holders CVC and Liberty Media could be announced on Wednesday.

However Ecclestone and CVC chairman Donald Mackenzie voiced some scepticism about the time frame at last weekend's Italian Grand Prix.

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