* Saudi banking heavyweights help push index higher
* Saudi Basic Industries adds 1.6 pct
* Oil prices at multi-year highs
* In Abu Dhabi, Dana Gas surges after deal with creditors
* Union National Bank falls after drop in Q1 net profit
By Tom Arnold
DUBAI, May 13 (Reuters) - Saudi Arabia's stock market led regional gains on Sunday as investors piled back into blue-chip stocks, while a slight retreat in oil prices from multi-year highs did little to deter buyers elsewhere in the Gulf.
The Saudi index closed 1.4 percent higher, with Al Rajhi Bank - the kingdom's second largest bank by assets and one of the main beneficiaries of a huge inflow of foreign money this year - climbing 1.5 percent. The largest, National Commercial Bank, climbed 3.0 percent.
The other big gainer was the biggest petrochemical producer, Saudi Basic Industries, which added 1.6 percent.
"The Saudi index has been off its highs over the past two weeks, so the smart money is recognising that as an opportunity and buying up blue-chips ahead of MSCI decision," said Nishit Lakhotia, head of research at Securities & Investment Co (SICO) in Bahrain.
"The market is not really reflecting the fact oil prices are close to three and a half year highs, and is still exhibiting strength which can significantly reduce state deficits for 2018 and potentially slow reforms that might be hurting consumers."
Saudi's largest stocks have attracted foreign inflows in anticipation of the upgrade of the stock market to emerging market status. In March, global index compiler FTSE Russell decided to upgrade Saudi Arabia to emerging market status, and MSCI is widely expected to make a similar decision in June.
Crude prices remain just below multi-year highs, despite slipping on Friday as it looked likely that U.S. allies would seek to maintain their nuclear deal with Iran, which could keep that country's crude exports on global markets.
In Abu Dhabi, Dana Gas was the most heavily traded stock, up 3.9 percent after the company said it had struck a deal with creditors on restructuring $700 million of sukuk, potentially bringing to an end a nearly year-long legal row that spooked investors in Islamic finance.
Shares in Abu Dhabi's Union National Bank fell 4.1 percent after it reported a drop in first quarter net profit to 425.6 million dirhams ($116 million), slightly below forecasts of SICO Bahrain and EFG Hermes.
Abu Dhabi's index dropped 0.3 percent.
In Dubai, the index closed 0.4 percent up. National Central Cooling Company (Tabreed) was the biggest gainer, closing 4.1 percent higher. The company said in a statement late last week, that it was considering new markets and countries in which to expand its operations.
In Egypt, the index added 0.2 percent. Qalaa Holdings surged 8.9 percent. The company said last week it was seeking to increase ownership in Egyptian Refining Co.
* The index rose 1.4 percent to 8,023 points.
* The index rose 0.4 percent to 2,892 points.
* The index dropped 0.3 percent to 4,425 points.
* The index climbed 0.8 percent to 8,817 points.
* The index fell 0.2 percent to 4,790 points.
* The index edged up 0.03 percent to 1,272 points.
* The index edged up 0.1 percent to 4,687 points.
* The index rose 0.2 percent to 17,184 points. (Additional reporting by Andrew Torchia; editing by John Stonestreet)