Mercedes-Benz is likely to delay an announcement about its customer engine plans for 2010, which was originally scheduled for this weekend's Italian Grand Prix.
The German car manufacturer's motorsport boss Norbert Haug had said in Belgium that he expected next year's engine deals to all be finalised by Monza, but the company's ongoing talks regarding taking an equity share in Brawn GP appear to have delayed matters.
Haug told AUTOSPORT: "We are not in a hurry and we are not quite sure when we will announce something. I said I hoped it would be before Monza, but I don't know if that will be the case now."
Mercedes-Benz already has engine contracts with McLaren and Force India for next year, and a deal with Brawn GP will also happen once discussions regarding an equity deal are complete.
The fate of a potential deal with Red Bull Racing remains unsure, however, with sources suggesting that an arrangement that had appeared near certain a few weeks ago could yet fall at the final hurdle.
The Milton Keynes-based team has been chasing a Mercedes-Benz deal for much of the season, and its recent reliability troubles with current supplier Renault had appeared to act as a catalyst for a deal to be signed with the German car manufacturer.
However, it is understood that Brawn GP's equity tie-up with Mercedes-Benz may have complicated matters - with sources suggesting that there are questions about whether it would make sense for the car maker to supply three potential title-winning teams.
Mercedes-Benz is keen, however, to supply four outfits with engines because of the commercial benefits.
Should the Red Bull Racing deal not happen, then speculation has linked Williams with a customer deal if it chooses not to pursue the option it has with Renault. Alternatively, Mercedes-Benz could limit its supply to three teams for 2010.
Haug has also confirmed that Rubens Barrichello will be able to re-use his Belgian Grand Prix engine in a race, despite the oil leak and fire he suffered at Spa.
"It's fine," he said. "It was a leak in the oil cooler, so the oil came out and burned. Finally in the pits it burned the engine, from the outside a little bit, but the engine is absolutely fine. He can race with it again."