The long-awaited ruling comes as Musharraf faces the prospect of Pakistan's second suspension from the Commonwealth since he took power in a bloodless 1999 coup, because he continues to resist calls to fully lift Emergency rule imposed on November 3.

"Dismissed," Chief Justice Abdul Hamid Dogar said after hearing the petition, the sixth and final challenge to Musharraf's October 6 re-election to be thrown out by the court.

Attorney General Malik Qayyum said before the ruling he expected Musharraf to be sworn in for a second term "by the weekend or immediately thereafter".

Musharraf's top legal adviser, Sharifuddin Pirzada, said there was now no legal obstacle to his re-election.

"Now the court has to give us this in writing," Pirzada said.

Musharraf repeatedly promised to relinquish his army post and be sworn in as a civilian leader for a second five-year term in what he calls a transition to civilian-led democracy once his re-election had been endorsed by the court.

While critical of his actions, the United States has given leeway to General Musharraf, a crucial ally in the fight against al-Qaeda and the Taliban, to put things right before a general election on January 8 that the opposition may boycott.

Western governments fear that stifling democracy could play into the hands of Islamist militants threatening nuclear-armed Pakistan.

Amid fears the Supreme Court would rule against him on the re-election challenges, Musharraf declared Emergency rule nearly three weeks ago, suspended the constitution, sacked the chief justice and purged the court, installing more amenable judges. The move drew widespread international condemnation.