The majority of prisoners - about 85% - come from the ruling Fatah party, which recently lost power to the radical Hamas movement in Gaza following violent street clashes. But Israel will not release a single Hamas prisoner.
Israeli Prime Minister Ehud Olmert Abbas made the pledge to Abbas during a two-hour meeting in Jerusalem earlier Monday.
In all, there are about 10,000 Palestinians in Israeli prisons.
A list of some 300 prisoners to be released was drawn up Sunday in line with a promise made at a meeting between the two leaders in Sharm el-Sheikh three weeks ago, and includes only security prisoners who have no "blood on their hands."
In addition to the release, which involves mostly Fatah supporters and a smaller contingent from the Democratic Front for the Liberation of Palestine (DFLP), and the Popular Front for the Liberation of Palestine (PFLP), Israel will call off the hunt for 178 wanted Fatah gunmen, and will allow DFLP leader Nayef Hawatmeh to travel to Ramallah Wednesday for a meeting with the Palestinian Liberation Organization's (PLO) central committee.
Hamas, which is considered a terrorist organization by the United States, Israel, and the European Union, won the first free and fair legislative elections to be held in the Palestinian territories in January 2006, defeating Fatah and setting the stage for the subsequent standoff.
A shaky coalition government established in March 2006 was dissolved in June 2007 after street fighting between the two factions, leaving Hamas in charge of the Gaza Strip, and Fatah in control of the West Bank.
Ironically, it was Israel that initially encouraged the creation of Hamas in the 1980s, seen as a useful counterweight to then-PLO leader Yasser Arafat. However, its radical Islamist agenda quickly metamorphosed into a potent political and social movement, gaining widespread support both for its uncompromising stance on Israel, as well as its many humanitarian and social welfare programs in the Palestinian territories.