Ron Dennis has only until the end of the season to take majority control of McLaren, the German publication Speed Week reports.
The team’s ’supremo’ is already chief executive, but it has been reported for some time that the 68-year-old has struck a deal to take over the 50 per cent stake held by Bahrain’s sovereign wealth fund.
But, according to Speed Week correspondent Gerhard Kuntschik, he only has until the end of November to get the money together. Whether Dennis can do that, Kuntschik added, is "an open question".
The report said works engine partner Honda is waiting for the situation to unfold, with "three major Japanese companies" in the wings as potential sponsors.
A lot could depend on McLaren-Honda’s ability to improve the MP4-30 package following an abysmal first half of the 2015 season.
Lead driver Fernando Alonso admitted in Hungary to some frustration.
"Before, when we had more freedom to test and improve the car, you could still end a season in a competitive way," he is quoted by El Confidencial newspaper.
"But now our hands are tied during the season. We test the car in Jerez and Barcelona and if it is competitive, you will have a good year. If not, you will have a bad year," said Alonso.