Tel Aviv - An ultra-Orthodox Israeli party has expressed reservations about entering a coalition headed by a woman, raising another hurdle for Foreign Minister Tzipi Livni in her efforts to form a new government.

Israel's Ma'ariv daily Thursday quoted a senior spiritual leader of the United Torah Judaism (UTJ) party, Rabbi Joseph Shalom Elyashiv, as saying in private talks this week that "it is not simple to sit in a government when the prime minister is a woman."

The party's rabbis have yet to issue a formal ruling in favour or against joining a government headed by a woman. They have said they will do so only when coalition negotiations reach a final stage.

But their reservations are based on a decree by a leading 12th century Jewish scholar, Rabbi Moses Maimonides, also known as the Rambam, who wrote that women should not serve in public office, Ma'ariv said.

Livni, 50, won the leadership of Israel's ruling party last month in primaries held to find a replacement for interim Prime Minister Ehud Olmert.

Olmert has resigned the premiership over suspicions of corruption and is currently serving at the head of a transitional government.

Israeli President Shimon Peres charged Livni with forming a new government late last month.

With the negotiations still in full swing, she will likely have to ask Peres for a two-week extension early next week, because the first 28-day period given to her by Israeli law to form the government ends Monday.

Her centrist Kadima party earlier this week signed a draft coalition agreement with the leftist Labour Party. With 19 mandates in the 120-seat Knesset, the Labour Party is the second-largest faction in the Israeli parliament after Kadima, which has 29. But she needs additional factions in order to obtain a majority.

So far, she has been unable to win over the ultra-Orthodox Shas party, which, with 12 mandates, is the third-largest faction, along with the hardline, opposition Likud.

The Likud of hawkish former premier Benjamin Netanyahu has already rejected her overtures and called for early elections, in which it is confident it would do well, based on opinion polls. Netanyahu has also tried to convince Shas not to join Livni's coalition.

Unlike UTJ, Shas has said it has no objection to joining a government headed by a woman. But it has refused to give in on two key demands - a raise in child allowances for large families, and a commitment that Livni will not negotiate on the status of Jerusalem in her talks with the Palestinians.

Livni met Shas leader Eli Yishai at the Foreign Ministry in Jerusalem Thursday afternoon. While Yishai wants an extra 1.5 billion Israeli shekels (more than 400 million US dollars) in child benefits for large - often ultra-Orthodox - families, Livni's aides have said she is willing to give only 500 million.

As for Jerusalem, aides said Yishai is willing to accept a verbal commitment and a handshake from Livni, rather than a written clause in the coalition agreement, promising no concessions on the disputed city.

Livni's representatives also met Thursday in Tel Aviv with the dovish, five-seat Meretz party, which has said it is willing, in principle, to join the government.

But Meretz lawmaker Zahava Gal-On told Israel Radio Thursday her party had no interest in joining a government that would not seek a peace deal with the Palestinians on all of the core issues of the Middle East conflict, including Jerusalem. Meretz also wants a freeze in settlement construction.

Livni has approached the UTJ, which has six mandates, as a means of raising the pressure on Shas. A coalition that would include that second ultra-Orthodox party would enjoy a majority even without Shas, her aides threatened.

But a senior UTJ official said his party was coordinating its positions with Shas, and would not join without it.

The main difference between the two ultra-Orthodox parties is that while the UTJ appeals mostly to Ashkenazi Jews, or Jews of European descent, Shas' constituency is made up mainly of Sephardic Jews, or Jews of northern-African and Middle Eastern origin. (dpa)