A representative of Hamas' rival, Palestinian President Mahmoud Abbas, denied however that such a deal was struck.
The understanding was reached between Western-backed Abbas and Khaled Meshaal, chief of Hamas, during one-on-one talks last week, said the Hamas figure.
He spoke on condition of anonymity, because he said the two leaders decided not to make the arrangement public.
Another top Hamas official, Moussa Abu Marzouk said that it was at least possible to skip an interim government and head straight to elections, tentatively scheduled for May.
However, Abbas envoy Azzam Al-Ahmed denied the two leaders reached such an understanding. "There is no possibility of holding elections without a unity government," he said.
Keeping the existing governments in place would help Abbas avoid a Western backlash in the run-up to elections. Western powers fear a unity government, even one composed of technocrats without clear political affiliation, would be heavily influenced by Hamas.
It also would mean that Salam Fayyad, an internationally respected economist, remains in charge in the West Bank for the time being and continue to ensure that donor countries keep funding Abbas' Palestinian Authority. Hamas will keep running Gaza, the territory it seized from Abbas by force in 2007.
