Mercedes will have to decide by October whether it wants to take part in next year's FIA Formula E championship.
Under a prior agreement, Mercedes-Benz Grand Prix has a guaranteed spot on the grid - provided that it chooses to exercise the option.
But the company has already missed the deadline to enter as a manufacturer, so it would have to be a customer team in 2018/2019.
The FIA has already signed-off on the list of powertrain manufacturers for next season. That means Mercedes would have to lease a motor, gearbox and inverter from one of the approved manufacturers.
"I think the interest is very strong," Formula E CEO Alejandro Agag told Autosport magazine. "But for 2018/19 if they come, they are not registered as a manufacturer.
"They will need to be a client of somebody. For 2019/20 they could come as a manufacturer.
"We'll see what they do, they still have their option until October, they can choose to exercise it or not."
Mercedes are currently contractually committed to Formula 1 until the end of 2020. Former team boss Eddie Jordan has suggested that Mercedes could quit the sport after that.
But that idea has been dismissed by Mercedes boss Toto Wolff. "The reports are completely baseless and reflect nothing more than the mischievous speculation of one individual," he said
If it opted to dip its toe into Formula E next season, Mercedes would be highly unlikely to want to partner with major rivals BMW.
That leaves DS, Mahindra, Renault, Jaguar, NextEV, Penske Autosport and Venturi as possible partners. Audi also supplies Formula E powertrains to the Abt team.
Agag has previously said that he also wants to see Ferrari enter the electric single-seater series. The sentiment was echoed by Ferrari's Sergio Marchionne who previously said that Ferrari "need to be involved" in the series.
"Electrification via hybridisation is going to be part of our future," he added.