(b)"State transport undertaking" means any undertaking providing road transport service, where such undertaking is carried on by,-(i)the Central Government, or a State Government;(ii)any Road Transport Corporation established under section 3 of the Road Transport Corporations Act, 1950; (64 of 1950.)(iii)[ * * *] [Clause (iii) omitted by Act 56 of 1969, section 38 (w.e.f. 2-3-1970).](iv)any municipality or any corporation or company owned or controlled by [the Central Government or one or more State Governments, or by the Central Government and one or more State Governments] [Substituted by section 38, Act 56 of 1969, for the words 'the State Government' (w.e.f. 2-3-1970).].