Dubai telecom operator du made its largest one-day gain in 10 months, surging to a four-year high and boosting the broader index after it posted quarterly results that beat analysts’ estimates. Most regional markets in the Gulf Arab region declined. Shares in du jumped 11.7 percent to AED 4.12 in its biggest gain since April 2012. Du’s fourth-quarter profit more than doubled to AED 994 million ($ 270.6 million) as it wrote back tax provisions. UAE telecom operators are taxed via royalties under license agreements with the federal government. The latter announced a new formula in December that includes a levy on revenues as well as profits. Du had provisioned to pay 50 percent of its profit in royalty fees through the year, but the new formula means it pays less tax as a percentage of profit than 2011, enabling it to write back some of the provisions it set aside in the first nine months of 2012. The firm also proposed a cash dividend of AED 0.3 per share. “The surprise was on earnings as well as dividend yield, which at 8 percent is very attractive,” said Ali Adou, portfolio manager at The National Investor. “The royalty fee restructuring will be negative for du after three years, but for the time being, the stock looks very attractive.” Dubai’s measure ose 1.7 percent to its highest close since November 2009. It has risen 16 percent year-to-date. Stocks have rebounded following tentative signs of recovery in Dubai’s property sector, but the share index remains about 70 percent below a 2008 peak. Abu Dhabi’s index eased 0.2 percent, down from Monday’s 39-month high. Elsewhere, Egypt’s index fell 1.2 percent to its lowest level in February as political uncertainty spurred foreign investors to cut risk exposure. Egypt’s constitutional court earlier rejected five articles of a draft election law and sent the text back to the country’s temporary legislature for redrafting in a ruling that may delay a parliamentary poll due in April. Investors are worried about the economic uncertainty caused by the delay, including a $ 4.8 billion loan from the International Monetary fund, seen as crucial to support the country’s battered economy and to stabilize a currency crisis. “The law debate makes it very difficult to expect when the elections will be held,” said Ahmed Kheir El Din, a Cairo-based trader. “We don’t know what will happen with the IMF (International Monetary Fund) loan or the appointment of a new government.” Non-Arab foreign were net sellers, while Arab were net buyers, bourse data shows. Commercial International Bank is the main drag, falling 3.2 percent. Orascom Telecom and Media sheds 1.4 percent and EFG-Hermes dips 2.8 percent.