* LIPA to restore last 15,000 Long Island outages post-Sandy * Flood-damaged homes need repairs before power restored * Fitch revises credit outlook on LIPA to negative By Scott DiSavino NEW YORK, Nov 13 (Reuters) - The Long Island Power Authority expects to restore service on Tuesday to most of its New York customers able to receive electricity, but more than 84,000 homes and businesses in New York and New Jersey will stay dark due to flood damage from Hurricane Sandy. LIPA, a New York State-owned power company, said it should hook up almost all of the remaining 15,000 homes and businesses that still lack service on Tuesday morning, more than two weeks after Sandy battered the region. But that number excludes customers within the flooded areas of Long Island that have yet to be surveyed for damage or may need repairs and certification by an electrician before the company can restore service, LIPA said. On Monday night, LIPA said about 38,000 homes and businesses were located within the flooded areas - 26,000 on the Rockaway Peninsula in New York City, 11,000 in Nassau County and 300 in Suffolk County. Other New York and New Jersey utilities had restored power by the weekend to most customers able to take service. However, thousands of customers remained without power due to flood damage - especially from seawater - which may have damaged electrical panels, wires, outlets and appliances, making it unsafe to restore electricity. In New York City, Consolidated Edison Inc said on Monday it still had about 16,300 customers in flood-ravaged areas of Brooklyn, Queens and Staten Island who could not regain electric service until they fixed their internal equipment. In New Jersey, FirstEnergy Corp's Jersey Central Power and Light utility has said about 30,000 customers on the barrier islands and shoreline communities could not have power restored due to infrastructure damage in that area. LIPA HIT HARDEST Sandy knocked out power to about 8.5 million customers in 21 states after hitting New Jersey on Oct. 29. More than 1 million of LIPA's 1.1 million customers lost power due to Sandy, while a nor'easter storm last week knocked out 123,000 more customers - thousands of whom had had power restored after Sandy. Combined, Sandy and the nor'easter knocked out more homes and businesses on Long Island than LIPA has customers. Despite the hard hit, New York Governor Andrew Cuomo has attacked all of the affected New York power companies - especially LIPA - for the slow pace of restoration. Fitch Ratings, a credit rating firm, on Monday revised its outlook on LIPA's $5.9 billion of outstanding electric system revenue bonds to negative. Fitch said the effects of Sandy would challenge LIPA's already tight financial flexibility and frustrate the authority's efforts to achieve improved financial performance. The cost of the Sandy restoration was uncertain but would likely exceed the $170 million LIPA spent to restore service after Hurricane Irene in August 2011, Fitch said. LIPA expects to recover about 75 percent of its Sandy-related restoration costs from the U.S. Federal Emergency Management Agency, Fitch said. Ratepayers usually cover unreimbursed storm costs. However, Fitch said LIPA's willingness to make customers pay more may be limited "given the intense political pressure surrounding LIPA's storm response and the authority's historic objective to moderate already high electric rates".