A deal to supply engines to the former Honda F1 team would have to be "100% bulletproof" to go ahead, the Mercedes motorsport boss has said.
There has been a high level of interest in Honda Racing since the announcement around Christmas that the team's parent was withdrawing from Formula One.
Last week chief executive Nick Fry revealed there are a dozen prospective buyers, down from an initial 30, keen to take over the team.
The team has been in limbo since Honda's withdrawal and even if a new owner is announced by the end of next week they will only have a short time to prepare for the new season opening with the Australian Gran Prix on March 29.
One of the difficulties may be finding an engine supplier, with the focus currently on Mercedes after the Ferrari team boss ruled out his marque.
Mercedes motorsport boss Norbert Haug said: "If there is a feasible solution with an investor for that team, we would be prepared to discuss it. But the financial background needs to be there."
Mercedes is a stakeholder in McLaren and has signed one deal to work with Force India for 2009.
© Press Association 2009