"The Swiss team has not extended its contract with Ferrari," correspondent Michael Schmidt revealed.
Currently, Honda's exclusive works partner is McLaren, whose now-ousted supremo Ron Dennis was earlier opposed to allowing the Japanese carmaker to sell its power unit to a customer.
Reportedly, Honda has completely redesigned its turbo V6 package for 2017, including Mercedes-like 'jet ignition', and a relocated turbine and compressor.
Schmidt continued: "For 2018, the Honda engine will be an option for customers. That is why the Japanese are currently expanding their factory in Milton Keynes, in order to serve two teams in the future."
It is believed Honda needs to know its 2018 plans by this year's Monaco grand prix.
But Auto Motor und Sport said Honda's only logical customer is Sauber, who will this year use a 2016-specification Ferrari power unit.
"There are rumours that preliminary talks between Sauber and Honda have already taken place," said Schmidt.