; (6) the employer shall use the public partner contribution solely for the purpose of providing compensation and benefits of the at-risk employee group and for no other purpose; and (7) the public partner contribution shall be utilized solely for compensation of United States-based employees. (d) Authority for public partner contributions The Secretary is hereby authorized to enter into agreements and to provide public partner contributions as envisioned under this Act. Such public partner contributions combined together with the private partner contribution shall be in an amount sufficient to maintain the total compensation level for the at-risk employee group as of April 1, 2020, for a term to be agreed, but for a duration lasting no more than 1 year. (e) No limit on number agreements with an employer An employer may seek and be granted public partner contributions under this Act on multiple occasions. (f) Coordination with secretary of transportation In implementing this section, the Secretary shall coordinate with the Secretary of Transportation. (g) Termination The authority established by this Act, and any agreement entered into by the Secretary under this Act, shall end on April 30, 2021. 4. Authorization of appropriations There is authorized to be appropriated, such sums as may be necessary to carry out this Act.