The Formula One Teams' Association are believed to be edging closer to an agreement with the FIA ahead of Friday's crucial announcement of the entrants for 2010.

FOTA have responded to a letter from FIA president Max Mosley after he urged them to this week submit an unconditional entry for next year.

Mosley made it clear if they did so, he would sit down with all the confirmed entrants and listen to their proposals with regard to the shaping of the regulations for 2010.

A FIA spokesperson said: "The FIA has received a letter and various attachments from FOTA, the contents of which are not entirely negative, and we are currently examining the details."

It is understood the eight remaining members of FOTA - Ferrari, BMW Sauber, Renault, Toyota, McLaren, Red Bull Racing, Toro Rosso and Brawn GP - are moving in the right direction.

Initially, all ten teams submitted a conditional block entry, only for Williams and Force India to since enter unconditionally due to contractual obligations.

The teams had insisted they would sign up through to 2012, but only if this year's regulations are in place for next season as they continue down their own path to cut costs.

FOTA were also looking for all parties - teams, FIA and Bernie Ecclestone's Formula One Management company - to re-sign the Concorde Agreement, a confidential commercial document governing the sport.

That prompted Mosley to write: "...the simplest way to ensure that all entrants run under the same rules would be if everyone entered under the cost-cap rules as published and then all entrants co-operated to agree modifications to those rules which would make the proposition workable for all parties."

With team principals and drivers stoking up the threat during the Turkish Grand Prix weekend of a break-away series should FOTA fail to reach a compromise with the FIA, such a prospect may be slowly starting to subside.