The deposit and lending rates of South Korean banks retreated in August from an 18-month high in the previous month as the prospects of a rate hike diminished, the central bank said Friday. The average rate for new loans extended to households and companies stood at 5.84 percent in August, down 0.02 percentage points from the previous month, according to the BOK. The August reading retreated from the 5.86 percent in July mainly because the BOK refrained from raising the key interest rate amid global economic uncertainty. The BOK said market rates such as returns on bank bonds declined as growing economic uncertainty stemming from the first-ever credit downgrade of the U.S. undercut market expectations for a rate increase. The BOK froze the benchmark rate at 3.25 percent for the third straight month in September as bleaker global economic outlooks outweighed concerns about persisting inflation. It had raised the borrowing costs in January, March and June. The average rate for household loans, however, added 0.12 percentage points on-month to 5.58 percent in August, mainly because local banks charged more on household lending despite falling market rates. Corporate loan rates, meanwhile, fell 0.06 percentage point to 5.92 percent. In August, market rates for certificates of deposit, which are tied to banks\' mortgage lending rates, shed 0.08 percentage point to 3.76 percent. The rate on mortgage loans, which account for the bulk of banks\' household lending, rose 0.07 percentage point to 4.97 percent last month, the BOK added. The average rate on bank deposits reached 3.77 percent last month, down 0.02 percentage point from July, according to the BOK. South Korean lenders\' loan-deposit spread, a gauge of banks\' profitability from lending, came in at 2.98 percent last month, down 0.02 percentage point from July, the BOK said.