Hamas, the largest militant Muslim group in Israel and the Palestinian territories,may renounce violence and transform itself into a political party. "We are discussing the formation of a new Islamic party and we will declare it at the appropriate time," Sheik Ahmed Bahar, a Hamas leader, said today in Jerusalem. "We express our opposition peacefully, not violently." Though Israel has delayed troop withdrawals from West Bank towns for nearly a year because of attacks by Hamas andthe smaller group Islamic Jihad, an official comdemnation of violence would remove a major obstacle inIsrael-PLO autonomy talks. Bahar, however, admitted that Hamas' political leadership could not control its armed wing, and another Hamas leader, Mahmoud Zahar, promised that attacks on Israelis would continue.