KARACHI (Reuters) - In the currency market, the rupee firmed to close at 84.40/45 to the dollar compared with Tuesdays close of 84.52/57 amid a lack of import payments and after the SBP received a $1.13 billion tranche of an International Monetary Fund (IMF) loan . Dealers said the rupee might strengthen in the short-term because of the arrival of the fifth tranche of the $10.66 billion loan but it was expected to weaken in the medium-term because of pressure from import payments.