Colombia's central bank held its benchmark interest rate for a tenth consecutive month on Wednesday, as policymakers grapple with the twin constraints of inflationary pressure and an economy weakened by the drop in global oil prices. The seven-member board voted unanimously to maintain the lending rate at 4.5 percent, meeting the forecast of all analysts in a Reuters survey earlier this week. Inflation has been above the bank's target of 2-4 percent since February, though the board expects it to come back within the range this year.