In a statement issued ahead of a meeting with the players' legal representative Chris Venturas in London on Friday, the ICC said the ZCU had agreed to a system that would see a three-person tribunal, sitting in Zimbabwe, resolve the impasse.
One member would be nominated by the ZCU, the other by the players, and the third, the chairman, by these two people.
The system, an alternative to its standard but lengthier disputes resolution process, has been specially devised by the ICC in a bid to end the crisis that has caused chaos in Zimbabwean cricket for several months.
In April the ZCU sacked then Zimbabwe captain Heath Streak after the fast bowler, now at English County Warwickshire, accused the Union of making some team selections based on race rather than merit.
When his colleague tried but failed to get Streak reinstated they went on strike in protest.
That led the ZCU to sack a total of 15 senior players, all white, a massive loss for a country with an already small pool of cricketers to choose from.
During ICC's executive board meeting, at its Lord's headquarters, on June 30 the governing body told both the ZCU and the players they had 14 days to agree to their three-man arbitration system.
In its statement the ICC said that while the ZCU had now agreed, the players were asking for an extra month to make up their minds.
However, the statement made clear that officials were not prepared to wait much longer.
"The ICC has advised the players of its strong preference to have this matter dealt with as quickly as possible and has expressed its reluctance to provide this extension which would leave these matters unresolved," the statement said.
"It has now asked the players to fast-track their decision on whether they will agree to this proposal to allow the matter to move to the next stage."
The bulk of the rebels are currently in England where they were playing the first match of a six-game charity tour designed to raise money for the Zimbabwean Cricketers Fund and the Zimbabwe Pensioners Fund.
Test batsman Stuart Carlisle, captain of the Red Lions, as the team is known, warned earlier: "It would be difficult to resume a working relationship with the ZCU because they have done so much damage and that's why the solution to the dispute has to be effective.
"Some of the individuals in the ZCU that have helped cause the problems have to be booted out of cricket completely. The cancer must be cleansed. If that happens then I'm sure we can work together."
The ICC, at the same board meeting that devised the tribunal system, suspended Zimbabwe's Tests for the rest of the year following heavy defeats against Sri Lanka.
However their One-day Internationals remained intact and England are due to play five such games in Zimbabwe in November.