Any person who is a member of any actuarially funded system paid for in whole or part from public funds, other than the State Employees' Retirement System of Louisiana, the Louisiana School Employees' Retirement System of Louisiana, and the Teachers' Retirement System of Louisiana, and who transfers to other public employment where he is no longer eligible for membership in the original retirement system but becomes a member of another actuarially funded system paid for in whole or part from public funds and who has creditable service in the first system for at least ten years, shall have the right to retain membership in the first system, and in the event he becomes eligible for retirement under this second system he shall be entitled to receive a pro rata benefit from each system, each such benefit to be calculated on the years of creditable service and the formula in use in the system from which the benefit is paid.
La. Consolidated Public Retirement § 11:141