Saudi Arabia is considering plans to increase an Islamic tax paid by local banks to as much as 20 percent, or double the current rate, according to people with knowledge of the matter, as the world's biggest oil exporter seeks to bolster alternative sources of revenue. Abu Dhabi headquartered NMC Health recorded its best ever net profit of $251.9 million (Dh925 million), helped on by a 20.4 per cent year-on-year increase. The revenue gains in percentage gains were just as strong, at $2.05 billion, an increase of 28.3 per cent.