6 Conclusions

The survey of the OH 1.6 GHz mainline emission in the direction of the CH₃OH 6.7 GHz maser sources provided eight new detections. For most sources the radial velocities of flux peaks in both maser lines differ by less than 3 km s^-1. In the sample of 68 northern methanol sources there are 19 objects not associated with OH masers. The sources without any OH emission have low $60~\mu$m flux densities (<1100 Jy). The peak flux ratio of OH to CH₃OH masers increases in sources with blue (60)-(25) colour possibly due to the evolution of star-forming regions.

Acknowledgements

We thank G. Hrynek for his assistance with the observations. This work was supported by the Polish State Committee for Scientific Research through grant 2P03D01415.