Williams have traditionally built their own gearboxes at their HQ in Grove, Oxfordshire, but the British team are currently evaluating the way they operate as they struggle for on-track performance.
Mercedes Team Principal Toto Wolff said there are discussions with Williams about extending their current engine supply arrangement to include the gearbox.
"We are in discussions about doing that," he said. "They are an engine client of ours. It’s not a huge thing to increase that to a gearbox.
“Nothing is signed, nothing is done and we need to decide in the next few weeks because the chassis design is at an advanced stage for Williams, so we’ll see how that pans out.”
There are a variety of different models used by teams up and down the pit lane, with Haas having particular success with their approach of taking all non-listed parts and the engine from Ferrari.
Williams Chief Technical Officer Paddy Lowe told Formula1.com the team "have our eyes open" to collaboration but reiterated that they have "a strong culture of being an independent, being a constructor".
He added: "Formula 1 is changing. Force India were one of the early ones to abandon the full constructor definition that teams had historically followed of essentially making everything except an engine.
“We’ve seen more and more teams adopting gearboxes from elsewhere. Now we have the Haas model where you adopt everything that is not listed.
“We have our eyes open to all of those possibilities because we owe it to ourselves. You’ve got to move with the times and do the best thing for the performance of the team.
“But having said that, Williams has a strong culture of being an independent, being a constructor, not only in the parts we are responsible for but also we are making them in-house.
“We have a capacity of manufacturing on our own site and we’ve prided ourselves on that. I don’t see us moving drastically away from that. But we remain open.”
Williams have scored just four points in 12 grands prix this year, leaving them bottom of the constructors’ championship.