One agency's head of broadcast said: "I am so surprised that ITV still hasn't managed to sell this one after last year's success with Lewis Hamilton.
"The asking price has plummeted from the original £4m to somewhere between £2m and £3m. People's reticence is down to the amount of investment in the brand it requires, especially in the current economic climate."
Gary Digby, managing director of ITV Customer Relations, said: "It's still in play. We are talking to three people and expecting to wrap it up by the end of this week or the early half of next week."
He would not comment on the price of the deal.
Richard Oliver, head of investment at Universal McCann, added: "ITV has always struggled with the F1 sponsorship. It's a good audience, but it's a very specific sector with a fairly narrow band of sponsors."
Honda sponsored ITV's 2007 coverage in a deal thought to be worth £2.5m.
On the back of Hamilton's performances, the average number of viewers per race in the 2007 F1 season increased by around 40%, to 3.3 million compared with 2006.
It was ITV1's highest average audience for any F1 season since 2001, pulling in an estimated £12m in extra ad revenue compared with 2006.