DUBAI, May 14 (Reuters) - Most Gulf stock markets edged down in early trade on Sunday with a much wider first-quarter loss at Saudi Arabia's PetroRabigh helping to pull down that market.
The Saudi stock index slipped 0.3 percent as PetroRabigh tumbled its 10 percent daily limit after reporting that its quarterly loss ballooned to 240 million riyals ($64 million) from 37 million riyals a year earlier, and compared to a profit in the previous quarter.
The company blamed the bigger loss, which contrasted with solid first-quarter earnings at many Saudi petrochemical firms, on reduced margins on refined products and a downtrend in crude oil prices, which hit inventory valuations. Also, it reclassified some payments and temporarily shut a facility in the first quarter.
The stock had been in a strong uptrend since mid-March in anticipation of good first-quarter earnings.
Medical insurer Bupa Arabia climbed 4.2 percent to 116.75 riyals after saying its international parent Bupa would increase its stake to 34.25 percent from 26.25 percent, by purchasing part of Nazer Group's stake. The planned purchase would occur at a price of 143 riyals per share.
But another insurer, MedGulf, plunged 10 percent after saying it had swung to a 93 million riyal loss in the quarter from a year-earlier profit. It cited a jump in provisions for doubtful debts and lower net underwriting income.
Dubai's index fell 0.5 percent as Islamic real estate finance company Amlak dropped 1.9 percent after reporting a net profit of 7.5 million dirhams ($2.0 million) for the first quarter; a year earlier, it had reported profit attributable to equity holders of 122.1 million dirhams.
Qatar's index slipped 0.4 percent, partly because of a 0.5 percent pull-back by Industries Qatar, which had rebounded for four straight days.
The Omani market edged down 0.2 percent after Standard & Poor's cut Oman's credit rating to junk status, saying low oil prices had eroded the country's external reserves to the point they could no longer offset the threat of low oil prices.
Trade was very thin. Analysts had expected banking stocks to be most vulnerable to the downgrade because it could mean the banks face higher costs in financing themselves, but while Bank Muscat and Bank Sohar fell modestly early on Sunday, National bank of Oman rose. (Reporting by Andrew Torchia)