“Kurdish lawmakers walked out of the session but the decision to reject the referendum was passed by a majority,” Mohammed al-Karbouli said.
Kurdish lawmaker Majid Shingali said Kurds would reject the decision.
“This decision has no value and we will not implement it,” he told Reuters.
Iraqi Prime Minister Haider al-Abadi’s government had previously rejected the referendum as unilateral and unconstitutional.
The United States and other Western nations fear the September vote in Iraqi Kurdistan could ignite a new conflict with Baghdad and possibly neighboring countries, diverting attention from the war against Islamic State militants in Iraq and Syria.
Turkey, along with Iraq, Iran and Syria, also opposes the idea of Iraqi Kurdish independence, fearing separatism could spread to their own Kurdish populations.
Kurds have sought an independent state since at least the end of World War One, when colonial powers divided up the Middle East and left Kurdish-populated territory split between modern-day Turkey, Iran, Iraq and Syria.