By HELENA BACHMANNOn the ninth floor of the Seef Tower in Manama, the small, opulent capital of Bahrain, the Noriba Bank offers its well-heeled clientele a wide range of financial services, from portfolio management to leasing. From its offices you can see the city's famous Al Fateh mosque. The proximity is significant, because even though Noriba, which opened in September, is wholly owned by Switzerland's largest bank, UBS Group, it is the only Western bank in the Gulf that insists that all of its services adhere to the strict letter of Islamic law, known as Shari'a.Compliance is neither easy nor cheap. The law, which derives from the Koran, covers all areas of Islamic life, including management of financial affairs. Pious Muslims are not...