An official with the leadership of a party present at the meeting says the Islamist Islah party pulled out of today's talks along with the Socialist and Nasserite parties.
The official says the group rejects dialogue with the rebels, known as Houthis, and calls for peaceful protests against them.
The parties also demand the release of a group of 11 activists and journalists the Houthis detained earlier in the day.
Officials with the office of UN envoy Jamal Benomar say he is continuing efforts to forge an agreement between Yemeni political forces.