SUNNY ISLES, FL-The Trump logo has found a place on six condo projects in Sunny Isles Beach since 2003. But many units remain dark and the volume of empty units is driving up vacancy rates in the oceanside city.

According to a new report from Condo Vultures, nearly half of the 1,000 finished condo units that remained unsold in Sunny Isles Beach at end of the third quarter are located in the six condo projects that carry the Trump name. Specifically, about 500 units of the 1,800-plus Trump-branded condos build on the ocean side of Collins Avenue since 2003 sit empty. The Trump Organization did not return calls seeking comment.

"The fact that such a large percentage of the Trump-named units are unsold has more to do with the number of condos constructed rather than the product type," says Peter Zalewski, a principal with the Bal Harbour, FL-based real estate consultancy Condo Vultures. The largest block of unsold Trump condos in Sunny Isles Beach is in Trump Tower III. As of the end of the third quarter, none of the 271 units in the building were sold, according to Miami-Dade County records.