High-spin states up to a probable spin [ital I]=45/2 have been investigated in [sup 219]Ac using the reaction [sup 209]Bi ([sup 13]C,3[ital n]). The alternating parity sequences already observed up to [ital I]=31/2 do not seem to develop further at higher spins. A new side band was observed as well as several [ital E]2/[ital M]1 transitions linking the states of positive parity. Multipolarities and mixing ratios were deduced from an analysis of DCO ratios. In addition mixing ratios were obtained independently from the branching ratios. This allows for determination of [ital B]([ital M]1)/[ital B]([ital E]2) ratios up to [ital I][sup [pi]]=29/2[sup +]. The data are discussed in terms of a transition from the weak coupling scheme at low and medium spins to the particle-hole regime for [ital I][approx gt]31/2.