US media giant Liberty recently bought the sport and ousted Bernie Ecclestone, and Westacott said Sydney could use the occasion to try to take over from Melbourne.
"It wouldn't surprise me," he told the Herald Sun newspaper.
"The world of events is very competitive."
But Westacott said there is no doubt the current contract, running until 2013, will run its course.
However, he said he is keen to show Ecclestone's successor Chase Carey next month that Melbourne is one of the best F1 hosts on the calendar.
"I would expect the new owners will be here to see how we do it and have a look at one of the very best formula one events in the world," said Westacott.