Aldar Properties and Sorouh Real Estate rose after both companies said they "remain in ongoing due diligence" over their proposed $13bn merger, propping up the capital's index in early trading.
"A decision on whether to recommend a merger to shareholders will follow the completion of these discussions which are at an advanced stage," the companies said in a joint statement to the Abu Dhabi Securities Exchange (ADX).
Aldar shares rose 0.7 per cent to Dh1.32 each before paring early gains, while Sorouh advanced 0.8 per cent to Dh1.25 each.
The two companies announced in March they were studying the possibility of a merger with the "blessing" of the Abu Dhabi Government.
Recent media reports had quoted senior Sorouh executives saying that the deal could be proposed to shareholders within "within a month."
Bankers with knowledge to the deal said they expect completion by the first quarter of 2013.
But sentiment was poor, with gains for Sorouh and telecoms giant Etisalat masking a despondent mood across the Emirates.
The Dubai Financial Market General Index fell 0.45 per cent to 1,601.66, while the Abu Dhabi Securities Exchange General Index rose 0.1 per cent to 2,638.23.
Etisalat rose 0.8 per cent, almost single-handedly keeping the capital's market measure in the green.
The Reserve Bank of Australia unexpectedly cut its main benchmark interest rate by 25 basis points to 3.25 per cent this morning.
Oil prices cooled slightly, with Brent crude futures down 4 cents to $112.25 per barrel.