The Municipal Transportation Agency’s 28-year history of outsourcing work for paratransit services is expected to move one step closer to being extended on Tuesday. The MTA’s paratransit service, which caters to passengers with disabilities, carried out more than 1 million trips last year and has over 14,000 registered customers, according to department statistics. On Tuesday, the MTA board of directors will vote on a five-year contract, worth $118 million, with Veolia Transportation, which has been supplying the department’s paratransit services since 2004. The MTA board is expected to approve the deal, although it still must get authorization from the Board of Supervisors, since the contract is worth in excess of $10 million. “Our paratransit is a key part to our transit system and this contract will allow us to continue to provide this crucial service,” MTA spokesman Judson True said.