* Dubai Q1 earnings jump 38 percent year on year
* The emirate's economic, property boom expected to continue
* Current valuations assume profits will surge further
* Abu Dhabi, Saudi Arabia post double-digit growth
* Qatar profits also rise, excluding Industries Qatar
DUBAI, May 8 (Reuters) - Dubai's bourse has outpaced other Gulf markets by a wide margin in terms of companies' first-quarter profit growth, data show, supporting its position as the top performer in the region.
The emirate's benchmark soared 108 percent last year and is up 57 percent this year, making it one of the world's top-performing stock markets over the past 17 months.
Although some analysts believe the market is overbought, its fundamentals have improved significantly.
The combined net profit of Dubai-listed companies that posted results by May 1 jumped 34.1 percent year on year, as calculated by Reuters based on data compiled by Kuwait's KIPCO Asset Management Company.
The figure does not include the earnings of Emaar Properties because the Dubai bellwether has yet to publish its full financial report. If Emaar's preliminary figures were included, it would lift Dubai's profit increase to 38.3 percent.
Banks and property companies dominate Dubai's bourse and some analysts think that structure partly explains the jump.
"Most of the stocks (in Dubai) are very cyclical, meaning that these companies are benefiting from the macro improvement in Dubai, which is why you have such a strong uptrend," Sebastien Henin, head of asset management at The National Investor in Abu Dhabi, said.
Others say that profits in the wider economy have risen by a similar margin, even if important sectors such as tourism and retail are largely absent from the bourse.
"I am pretty sure business across sectors is doing very well, especially in areas such as hospitality, retail and transport," Amer Khan, senior executive officer at Shuaa Asset Management, said. "It all points to a significantly improving economy, and that is trickling down into earnings."
Dubai's economy is expected to grow by about 5 percent this year, a similar pace to 2013. Selling prices for residential property rose by about a third in the first three months of the year compared with the same period in 2013.
"Whether (the current valuations) are justified will depend on whether this growth continues," Khan said.
ABU DHABI, SAUDI IN DOUBLE DIGITS
Earnings in Abu Dhabi have risen 11.6 percent. This was largely thanks to First Gulf Bank and telecoms operator Etisalat, which posted profit increases of 27.2 percent and 10.9 percent respectively, accounting for 54 percent of Abu Dhabi companies' combined quarterly profits.
In Saudi Arabia, total reported profit from listed companies rose 10.9 percent. Excluding Saudi Basic Industries, which accounted for a quarter of total earnings and which suffered a 1.8 percent profit fall, combined profits rose 15.8 percent.
Overall, Saudi petrochemical companies achieved a 15.8 percent profit rise, led by Rabigh Refining and Petrochemical Co swinging to a 413 million riyal ($110 million) profit after a loss of 658 million riyals.
Saudi banks, meanwhile, achieved a profit increase of only 1.8 percent. Al Rajhi Bank, the kingdom's largest listed lender, reported a 17 percent slump in profit for the quarter while most of its rivals posted double-digit growth.
Qatar's bourse has officially reported that the combined first-quarter net profit of all but two companies amounted to 11.1 billion riyals, up 8.6 percent year on year.
With the exclusion of Industries Qatar, which accounted for 14 percent of the total and whose profit shrank by more than a third, Qatar's growth rate would rise to 24 percent.
"These are all good numbers. It underpins the advance in share prices that we have seen in the past six months," Shuaa Asset Management's Khan said, referring to the figures for Abu Dhabi, Qatar and Saudi Arabia.
The three bourses' benchmarks have trailed Dubai in terms of gains since the start of 2013, but are ahead of other regional markets.
Other Gulf markets were firmly in single digits. Total reported profits in Kuwait rose 5.5 percent, according to Thomson Reuters data, while Bahrain's companies posted a 6.6 increase, data compiled by KIPCO showed.
The available data on earnings in Egypt and Oman was not sufficient for meaningful comparisons. ($1 = 3.7505 Saudi Riyals)
(Editing by Matt Smith and David Goodman)