Global Motorsport Media
Up to three races on the 2012 calendar are endangered, according to a Brazilian media report.
The O Estado de S.Paulo newspaper reports that the events scheduled in Korea, the United States and Bahrain will be discussed during Thursday's F1 Commission meeting in Geneva.
An unprecedented 20 Grands Prix have been scheduled on the 2012 calendar, but Bernie Ecclestone will tell the teams on Thursday that the Korean organisers are hesitating on paying the sanctioning fee deposit.
"It took us long enough to negotiate with them in the first place," the F1 chief executive told reporters in India last weekend.
"It was strange. That was a disappointment because it was a big enough effort to get it on in the first place."
Brazilian correspondent Livio Oricchio also said that, shortly after a New York street race was announced for 2013, there is now a question mark about the 2012 US Grand Prix scheduled for a new venue near Austin, Texas.
And finally, it is the "political situation" in Bahrain that has triggered the F1 Commission talks about the island Kingdom's 2012 return.
"It is almost certain that the fourth round, on April 22, will not be contested," the Brazilian report reads.
And it seems clear that the teams will not be unhappy if the schedule dips below 20 Grands Prix next season.
I think 20 races and a lot of flyaways is pretty hard on the teams
McLaren and FOTA chief Martin Whitmarsh confirmed there are "some question marks" about some of next year's scheduled events.
"I think 20 races and a lot of flyaways is pretty hard on the teams and I think we are at tipping point," he said.
"You are getting close to the point where you do need to alternate. It's the NASCAR approach where you alternate crews."