KIEV, Ukraine (AP) -- Marathon talks to end Ukraine's political paralysis broke off early Saturday without an agreement between President Viktor Yushchenko and the pro-Russian parliamentary majority that has nominated his former Orange Revolution rival as prime minister.

Yushchenko spent more than 10 hours negotiating with Victor Yanukovych and the country's new parliament speaker, Oleksandr Moroz.

Yanukovych's nomination as premier earlier this month was an embarrassing setback for Yushchenko, whose popular support has suffered amid infighting and allegations of corruption and incompetence against his government.

The rivals were negotiating a national unity agreement that would lock Yanukovych into the president's pro-Western and reformist policy goals. The agreement would commit the former Soviet republic to work toward joining NATO, the European Union and the World Trade Organization, and would safeguard Ukrainian as the sole national language.

While it would not be legally binding, the accord would represent a significant compromise for Yanukovych, who had campaigned on making Russian a state language and improving ties with Moscow. There was no specific mention of Russian in the draft agreement.

Ukraine has been in political turmoil since March parliamentary elections ended without a clear winner. Yanukovych's pro-Russian Party of Regions won the most seats, but fell short of a majority.

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

Earlier this month, Yanukovych's party formed a majority coalition with the Socialists, who bolted from Yushchenko's alliance, and the Communists. The agreement would open the door for Yushchenko to join the new coalition.

"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.

She said the main areas of disagreement were over the question of the national language, NATO and the Party of Regions' support for decentralizing power. Yushchenko has also opposed Yanukovych's candidacy for premier and including the Communists in the coalition.

Yushchenko, who has warned he might use his right to dissolve parliament and call new elections, has until Wednesday to decide whether to approve Yanukovych's bid for prime minister. On Friday, a top member of Yushchenko's party made clear that such a prospect was still unwelcome. "We need to find a person who can consolidate the country," said Anatoliy Kinakh. "Yanukovych's is not such a candidacy."

Gerashchenko said the president, who had been determined to reach an agreement overnight, would summon leaders back later Saturday after they consulted with their parties.