LetA be aC*-algebra andG be a locally compact group acting as strongly continuous automorphisms onA. Let π be a representation ofA then we say π is a covariant representation if there exists a strongly continuous unitary representation of the group acting onHπ which implements the automorphisms. We give necessary and sufficient conditions on a representation π ofA such that a) π is subrepresentation of a covariant representation and b) π is subrepresentation of a covariant representation quasi-equivalent to π.