High sensitivity observations of all four transitions of the ground state at 18cm of OH in both senses of circular polarization have been carried out with the Nancay radio telescope. The sample was a set of 100 star forming regions detected in a recent unbiased survey of 6668MHz methanol masers (Szymczak et al., 2002A&A...392..277S). OH maser emission was found in 55 objects of which 31 were not previously catalogued.