A member of Iraq's Governing Council said earlier Izzat Ibrahim al-Douri, the highest-ranking former regime official still at large aside from Saddam himself, had been caught during the raid near Kirkuk.
But Major Doug Vincent of the 173rd Airborne Brigade told reporters al-Douri was "definitely not captured in today's mission".
The United States has posted a $10 million reward for the capture or death of al-Douri, believed one of the key guerrilla organizers of recent attacks around Samarra and Tikrit.
Saddam Hussein biographer Simon Henderson told the BBC the capture of al-Douri would be "a considerable victory for the Americans and a considerable defeat for the insurgency".
Al-Douri was one of the key plotters who carried out the coup that brought the Baath Party to power in 1968. In later years, he served as vice chairman of the powerful Revolution Command Council.