Toyota, BAR-Honda, Renault, McLaren-Mercedes, BMW Williams and Minardi signed the memorandum while three remaining teams – Sauber, Jordan-Midland and Red Bull – said that they would report back to their owners after the meeting.
Car manufacturers behind the breakaway series say Formula One teams will join their championship on equal terms.
BMW, DaimlerChrysler, Renault, Honda and Toyota have promised a more equal share of the money distributed to teams as well as the possibility of affordable and competitive engines to those that sign up.
Money is currently distributed to teams within Formula One according to status and results, with Ferrari receiving more cash than their rivals.
Ferrari was the only team that did not attend the meeting.
A GPWC statement said all parties had fully endorsed governing principles published last month by the manufacturers.
The current Concorde Agreement governing F1's commercial side comes to an end in 2007, and the GPWC is hoping to establish a new series in 2008.
