Attendance at this year's International Consumer Electronics Show could be well below organizer estimates, according to preliminary data released by the Consumer Electronics Association on Sunday.

The show, which opened with Microsoft CEO Steve Ballmer's keynote last Wednesday night and ran through Sunday, attracted "more than 110,000" people, according to the preliminary estimates. Before CES began the organizers said they expected "more than 130,000" people to attend the show.

Fully audited figures are due in about 90 days and could push that estimate up or down. Last year the CEA had estimated 130,000 attendees, but the audit reported 141,150 attendees.

Before CES 2009 began there were worries about attendance. While attendees must typically book their stays several months in advance, this year major hotels in Las Vegas had rooms available throughout CES week.

When the show began, the corridors and hallways appeared less congested than in past years to many observers. On Sunday the aisles of the central hall, which are home to most of the biggest names in consumer electronics, were largely absent of visitors and in some of the other halls exhibitors started dismantling their booths before the 4 p.m. end of the show.