The parties have been at loggerheads over the F1 chief executive's refusal to offer to Mercedes the same Concorde Agreement deal reached with other top teams Ferrari, McLaren and Red Bull.
In response, it has been suggested not only that the situation threatened the sport's floatation plans, but that Mercedes could sensationally quit F1 at the end of this year.
"We are now 80 per cent there," Ecclestone told the German newspaper Bild am Sonntag in Barcelona.
"The other 20 per cent, we will get there soon," he added.
"We have spoken with several Mercedes managers. I am sure we will see more of Mercedes in formula one."
Bild said the deal being discussed between Ecclestone and the Stuttgart based carmaker will see Mercedes in F1 at least through 2020.
Norbert Haug, however, sounded surprised.
"I have to apologise, but we don't want to give any information at the moment about the state of the negotiations," Mercedes' motor racing vice-president insisted.