NY -- Standard&Poor's CreditWire 4/16/96 -- Standard&Poor's assigns its `A-3' short-term rating to the Republic of Argentina's peso-payable Letras del Tesoro (LETES). US$250 million pesos of three-month LETES are expected to be auctioned today. Issues rated `A-3' are investment-grade. The Letras del Tesoro program contemplates the issuance of $2 billion in short- and long-term securities this year, potentially in both pesos and U.S. dollars. Long-term (maturities of more than one year) peso-payable obligations would be rated triple-`B'-minus, with a stable outlook. Long-term dollar-payable obligations would be rated double-`B'-minus, with a stable outlook, while short-term dollar-payable Letras would be rated single-`B'. At the same time, Standard&Poor's today has affirmed its double-`B'-minus rating and stable outlook