CAIRO - Egyptian President Mohamed Mursi has cancelled a decree that gave him sweeping powers and sparked deadly violence, but did not delay this month's referendum on a new constitution as his opponents had demanded.

The announcement that Mursi had scrapped his November 22 decree followed hours of talks on Saturday at his presidential palace, billed as a "national dialogue" but which was boycotted by his main opponents and had little credibility among protesters.

One opposition group dismissed Mursi's efforts at appeasement as the "continuation of deception."

His opponents have demanded Mursi scrap the vote on December 15 on a constitution that was fast-tracked through an assembly led by Mursi's Muslim Brotherhood and other Islamists. Liberals and others had walked out, saying their voices were not being heard.

Islamists have insisted the referendum should go ahead on time, saying it is needed to complete a democratic transition still incomplete after Hosni Mubarak's overthrow 22 months ago.

The military, which had run the nation during a turbulent interim period after Mubarak fell, stepped into the crisis on Saturday to tell feuding factions that dialogue was essential to avoid "catastrophe." But a military source said that was not a prelude to the army retaking control of Egypt or the streets.

After Saturday's talks, the president issued a new decree in which the first article "cancels the constitutional declaration" announced on November 22, the spokesman for the dialogue, Mohamed Selim al-Awa, told a news conference held around midnight.

But he said the constitutional referendum would go ahead next Saturday, adding that although those at the meeting had discussed a postponement, there were legal obstacles to taking such a step.

The political turmoil has exposed deep rifts in the nation of 83 million between Islamists, who were suppressed for decades, and their rivals, who fear religious conservatives want to squeeze out other voices and restrict social freedoms. Many Egyptian just crave stability and economic recovery.