DUBAI, July 23 (Reuters) - Dubai's stock market outperformed a quiet region in early trade on Sunday as Islamic finance firm Amlak AMLK.DU jumped for a second straight day in very heavy trade.

The Dubai index .DFMGI added 0.6 percent as Amlak AMLK.DU surged 8.0 percent to a four-month high of 1.21 dirhams and was the market's most active stock, accounting for nearly a quarter of turnover.

It rose above its 200-day average, now at 1.14 dirhams, for the first time since February. On Thursday, it had soared 14.3 percent.

Traders attributed the rise to last week's announcement by real estate developer DAMAC DAMAC.DU that it was partnering with Amlak to sell second homes to customers. However, the partners gave no financial details, and many investors piled into the stock just because it had momentum. DAMAC rose 1.3 percent early on Sunday.

Abu Dhabi's index .ADI fell 0.3 percent as Abu Dhabi Commercial Bank ADCB.AD dropped 0.7 percent. It reported a 10.4 percent fall in second-quarter net profit to 1.01 billion dirhams ($275.2 million); three analysts polled by Reuters had on average forecast 1.11 billion dirhams.

Qatar .QSI was flat as Gulf International Services GISS.QA , the most active stock, rose 1.44 percent. But the banks which led last week's rally stalled, with Qatar National Bank QNBK.QA edging down 0.1 percent.

Qatar's stock market has regained almost all of the losses it suffered after the country's diplomatic crisis with its neighbours erupted on June 5. At the weekend, Qatar's emir called for dialogue but gave no clear sign of a fresh initiative to end the crisis; United Arab Emirates Minister of State for Foreign Affairs Anwar Gargash said Doha needed to change its policies before a dialogue could occur.

Saudi Arabia's index .TASI was also flat after half an hour. Alinma Bank 1150.SE , the most active stock, rose strongly for a third straight day after reporting better-than-expected second-quarter earnings last week; it added 2.0 percent.

Arabian Shield Cooperative Insurance 9070.SE surged 3.8 percent after reporting second-quarter net profit more than doubled from a year ago. Arab National Bank 1080.SE climbed 1.3 percent after reporting a 4 percent rise in quarterly profit.

But Yamamah Cement 3020.SE dropped 1.5 percent after disclosing that second-quarter profit plunged to 12.2 million riyals ($3.3 million) from 116.3 million riyals; sales also fell sharply.

(Reporting by Andrew Torchia; Editing by Toby Chopra) ((andrew.torchia@thomsonreuters.com; +9715 6681 7277; Reuters Messaging: andrew.torchia.thomsonreuters.com@reuters.net))