A key interest rate in Saudi Arabia, the biggest Arab economy, rose to its highest in six years as liquidity at banks tightens amid the plunge in oil prices. The three-month Saudi Interbank Offered Rate, a benchmark used to price loans, rose 0.4 basis points to 1 percent on Thursday, the highest since April 14, 2009, according to data compiled by Bloomberg. The rate has climbed 23 basis points since this year’s low in March. Bank loans in Saudi Arabia, the world’s biggest oil exporter, have expanded 9 percent in the 12 months through August, faster than the growth in customer deposits of 8.3 percent over the period, according to central bank data. The government has borrowed at least 55 billion riyals ($15 billion) from local banks and institutions through bond issues this year to bridge a fiscal deficit, which the International Monetary Fund expects to climb to more […]