Toto Wolff has flagged a new "multi-year" contract with Nico Rosberg.
Mercedes team chairman Niki Lauda hinted at a new two-year contract for the championship leader last week, but German Rosberg denied that anything is signed.
"With myself, Gerhard Berger and Niki Lauda, you have three Austrians in the room negotiating and it's difficult," team boss Wolff smiled, according to Speed Week.
"Seriously, the details are being cleared up. Nico will get a multi-year extension, but it's not signed yet," he added.
As for the future, Wolff said that Mercedes is well positioned with Pascal Wehrlein and joined Red Bull in playing down suggestions of a deal with Mick Schumacher.
"We have no plans with him," Wolff said. "The boy will go on with his development in peace."
Wolff was also asked about the likely 2017 debut of the updated 'Halo 2' concept, warning that the safety boost could come with "disadvantages".
"What if the car is upside down and something happens? There is a horror scenario with these batteries that a fire can start that cannot be put out - I don't want to see trapped drivers," he said.
The season continues with the Austrian Grand Prix tomorrow.
