At the other end of the equation, Citicorp figures to gain a paltry $80 million in reserves, S&P said. The report, written by analyst Tanya Azarchs and released Monday, represents the first estimate of individual banks' excess reserves in light of recent debt restructuring agreements with Argentina and Brazil. Analysts said Monday that they had already calculated the effect of the debt pacts and therefore would not change earnings estimates as a result of the study. S&P found that major U.S. lenders to the Third World have a total of $2.6 billion in excess loan-loss reserves.. J.P. Morgan & Co.'s excess reserves were put at $400 million, while Bankers Trust New York Corp.'s were $200 million. Because both companies have already reallocated Third World reserves, they have already accrued that benefit. Chase Manhattan Corp., which has a large amount of domestic nonperforming loans, has $230 million in excess reserves.