Formula 1 has delayed the first of two deadlines for teams to sign up to be part of the championship from 2021.
Teams were in line to receive a bonus if they committed to F1 by 12 August, but that deadline has been moved back six days to allow time for more talks.
F1 said: “We have received some final small legal comments that are being considered so the early sign-on deadline has been moved to 18 August.”
The final deadline for teams to commit remains the end of the month.
Ferrari, McLaren and Williams said at the 70th Anniversary Grand Prix last weekend that they were ready to commit to the next contractual period from 2021-25 on the terms currently on offer.
However, Mercedes have made it clear there are still some outstanding issues it wants to resolve before it will sign up.
F1 has restructured the sport so that there will be a more equitable split in prize money between the teams. That will reduce the huge disparity between the big teams and less successful ones – created by former chief executive Bernie Ecclestone in the current contracts, which were negotiated in 2011.
Mercedes F1 boss Toto Wolff said last Friday that the company had “legal, commercial and sporting issues” with the new contracts.
He added that he had not seen any willingness to compromise from F1.
F1 responded by saying it had “engaged with all the teams in a collaborative and constructive way” and that the agreement would “not be delayed any further”.
On Sunday, Wolff said: “What F1 wants to achieve is that it’s not being dragged out any further.
“They have set the deadline and made it clear that we have to get on and sign the Concorde Agreement. I don’t think that if anyone fails to meet the 12th or large corporations need more time, this is going to be an issue.
“This is a partnership; they need the teams and we need a strong commercial rights holder.
“I know why they put a line in the sand to get everyone acting, and they have been pretty successful with that.
“I would not pin it down to a day or two or a few weeks. It is a matter of getting the assurances and the buy-in and commitment from the teams to move on and settle it quickly.”
Mercedes is committed to F1 and wishes to stay involved but Wolff’s comments betray an unhappiness with the terms on offer.
Insiders say Wolff is pushing for more money from F1 as what he regards as a fairer recognition of Mercedes’ contribution to and role in the sport.
Under the new agreement, the massive bonuses paid to the big teams have been removed.
These saw Ferrari last year earn about an additional $110m (about £84m), Mercedes and Red Bull more than $70m (£53.7m), McLaren about $30m (£23m) and Williams $10m (£7.7m).
The new system will see Ferrari earn $40m (£30.7m) for its long-term commitment to the sport as the only team that has been in the championship since its inception in 1950.
The engine manufacturers will each receive payments of $10m (£7.7m) a year in recognition of their support for the sport.