WASHINGTON (Reuters) - Unions and trade groups are seeking at least $112.8 billion in additional government assistance to rescue the struggling U.S. transport sector hit hard by the collapse in travel demand because of the COVID-19 pandemic, according to a Reuters review of funding requests. Several of the new requests have been made since Friday. With millions of workers and would-be tourists staying at home, the groups seek: * $39.3 billion in emergency funding for public transit systems sought by the American Public Transportation Association (APTA) and several transportation unions. * $40 billion for U.S. motorcoach, school bus and passenger vessel and ferry companies. ADVERTISEMENT * $15 billion sought by aviation unions to keep airline employees in their jobs after March 30, when the latest government assistance package expires. * $17 billion sought by Airports Council International–North America and the American Association of Airport Executives in a previously unreported Jan. 13 letter to help “pay for debt service on their bonds, (and) keep their critical health, safety, and security projects on track.” * $1.5 billion in additional emergency assistance sought by U.S. passenger railroad Amtrak through Sept. 30, which has received $2 billion in emergency funding from Congress since March. That funding is in addition to the $2 billion in annual government support it received for the current budget year. Congress has approved $39 billion since March 2020 to aid transit systems, including $14 billion in December. It awarded $40 billion to date in payroll assistance for U.S. airlines, $12 billion for airports and airport concessionaires and $2 billion for bus and vessel industries. ADVERTISEMENT President Joe Biden has called for $20 billion for mass transit in a $1.9 trillion COVID-19 relief bill. The transit unions and association said on Monday that transit systems need government help to “provide safe, reliable service.” The bus and vessel groups said in a letter on Monday the $2 billion awarded in December is not expected to be released by the U.S. Treasury for several months and “is woefully inadequate to help all our essential industries return to anything close to pre-pandemic health.” Reporting by David Shepardson; Editing by Leslie Adler and Howard Goller