* Militant Hamas and Western-backed Fatah split in 2007 * Abbas expected to swear in new ministers soon * Security questions put off until after elections (adds quotes, background) By Nidal al-Mughrabi GAZA, May 27 (Reuters) - Rival Palestinian factions Fatah and Hamas agreed on the make-up of a national unity government on Tuesday in the most significant step yet toward healing their seven-year rift. Officials from the two sides told a news conference in the Gaza Strip that Palestinian President Mahmoud Abbas will make a formal an**uncement of the new government later this week after choosing a religious affairs minister. "The viewpoints of the Hamas and Fatah movements will be presented to President (Abbas) to give his final decision on the government line-up," Fatah official Azzam al-Ahmed said. The deal cements an initial unity pledge the two parties an**unced on April 23, just as U.S.-backed peace talks Abbas was holding with Israel were collapsing.