The marathon crisis talks to end Ukraine's four-month political paralysis broke off early Saturday without any agreement between President Viktor Yushchenko and the pro-Russian parliamentary majority that wants to put together the next government in this ex-Soviet republic.

Yushchenko spent more than 10 hours in closed-door negotiations with his former Orange Revolution rival Viktor Yanukovych and the country's new parliament speaker Oleksandr Moroz in a bid to reach agreement on a memorandum of national unity. The agreement is an effort to lock Yanukovych, who has been nominated to become prime minister, into the president's pro-western and reformist policy goals, and could open the door for Yushchenko's party to join a new coalition.

Ukraine has been in political turmoil since Yanukovych's pro-Russian Party of Regions won the most seats in the March parliamentary elections, besting the pro-Western reformers who backed Yushchenko, but falling short of a majority.

The Party of Regions formed a majority coalition earlier this month with Yushchenko's one-time partners, the Socialists, and the Communists. They proposed Yanukovych, whom Yushchenko defeated for the presidency in 2004, as prime minister.

"The negotiations ended because the leaders of the Socialist Party and the Party of Regions want to discuss the text of the memorandum with their political parties," said the president's spokeswoman Iryna Gerashchenko.

The draft memorandum, which consists of 24 points, commits Ukraine to working toward NATO and European Union membership, safeguarding Ukrainian as the sole state language, joining the World Trade Organization, advancing liberal economic reforms and promoting transparency in government.

While it is not considered legally binding, the agreement would represent a significant compromise for Yanukovych, who campaigned on making Russian a state language, expanding power to Ukraine's regions and improving ties with Russia. There was no specific mention of Russia in the original agreement.

Gerashchenko said the main areas of disagreement were over the question of language, NATO membership and the Party of Regions' support for decentralizing power in the country.

Yushchenko had been determined to reach agreement overnight, but after nearly nine hours the talks broke off early Saturday with no breakthroughs. The president appealed to the exhausted leaders to return to the table, and the talks continued for another two hours, before breaking again.

Gerashchenko said Yushchenko would summon the party leaders back later Saturday after they had time to consult with their parties.

Meanwhile, it remained unclear if any progress had been made on the two biggest stumbling blocks: Yanukovych's candidacy to be prime minister and the refusal by the president's party to cooperate in a coalition that includes the Communists. Neither is directly addressed in the draft memorandum.

Yushchenko has until next Wednesday to decide whether to approve Yanukovych, whom Yushchenko defeated for the presidency in a court-ordered revote in 2004. The revote was held after mass protests, known as the Orange Revolution, erupted over Yanukovych's fraud-marred victory.

Earlier Friday, a top member of Yushchenko's party made it clear that such a prospect was still unwelcome.

"We need to find a person who can consolidate the country. Yanukovych's is not such a candidacy," said Anatoliy Kinakh.

The standoff has highlighted the split between the largely Russian-speaking east of Ukraine, where Yanukovych's support is strongest, and the more nationalistic, Ukrainian-speaking west.

Yushchenko has previously warned that he could use his right to dissolve parliament and call new elections, a move that some warn could trigger civil unrest.