UPDATE 2: Arabtec, Emaar shares fall, while real estate stocks weigh on Abu Dhabi's index.
Dubai's index slipped to a six-week low, reversing the previous day's gains as investors booked profits ahead of the weekend.
Arabtec fell 1.7 percent, having gained 2.6 percent on Wednesday ahead of an after-market announcement saying the builder had won $202 million of contracts.
"Combined, the projects represent another step in Arabtec's expansion around the MENA region and diversification away from Dubai, where construction conditions are likely to remain subdued for some time," Ian Munro, MAC Capital head of research, wrote in a note to clients.
"The combined projects are likely to add 2.4 percent to annualised EPS (earnings per share) during FY10 and FY11. We retain an Overweight recommendation and price target of 3.67 dirhams on Arabtec."
Emaar Properties also slid, falling 2.4 percent and Dubai Financial Market dropped 2.5 percent as losers outnumbered gainers 15 to zero.
The index falls 1.3 percent to 1,655 points, rising slightly from an intraday low of 1,649 points, its lowest level since Dec. 13.
Property stocks tumbled, weighing on Abu Dhabi's index which fell for the eighth day in nine as Dubai's debt woes spurred selling in the UAE capital.
Aldar Properties fell 3.3 percent and Sorouh Real Estate dropped 2.8 percent.
Abu Dhabi's benchmark fell 0.2 percent to 2,648 points.
Kuwait banks slumped on fears of more lenders announcing capital increases to cover rising provisions, weighing on Kuwait's index.
National Bank of Kuwait fell 1.8 percent, taking its losses to 3.6 percent since announcing plans for a 10 percent capital hike on Monday, while Kuwait Finance House declined by the same margin.
Burgan Bank was down 10 percent since it said it had received approval to raise its capital on Dec. 13.
Commercial Bank of Kuwait dropped 4.1 percent, giving back all its gains since saying its entire board resigned.
The index slipped 0.04 percent to 7,059 points.