In March two other men were given the same sentence for the same offence.
Under Palestinian law, those convicted of collaboration with Israel, murder and drug trafficking face the death penalty.
Execution orders must be approved by the Palestinian president before they can be carried out, but Hamas no longer recognises the legitimacy of Mahmud Abbas whose four-year term ended in 2009.
The militant Islamist Hamas has carried out formal executions ordered by its courts and summary, sometimes public, killings of "collaborators" condemned by "revolutionary tribunals".
