Downer EDI has swung back into profit, with the contracting giant telling investors it was considering exiting its joint venture with French public transport operator Keolis after losing Melbourne’s lucrative Yarra Trams contract.

The Downer Keolis joint venture, which has run Melbourne’s tram network since 2009 and operates other light rail, heavy rail and bus contracts, will hand over management to Transdev and John Holland in December after losing a $6.8 billion tender in July.