dubai dec 15 reuters  the saudi central bank said on wednesday it increased its key interest rates by 50 basis points following the us federal reserves move as the saudi riyal is pegged to the dollar the saudi central bank also known as sama lifted its repo and reverse repo rates by 50 bps to 5 and 45 respectively it said in a statement reporting by mahmoud mourad and yomna ehab in cairo writing by yousef saba in dubai