A catalog of rotational and radial velocities for evolved stars - IV. Metal-poor stars

Aims. The present paper describes the first results of an observational program intended to refine and extend the existing v sin i measurements of metal-poor stars, with an emphasis on field evolved stars. Methods. The survey was carried out with the FEROS and CORALIE spectrometers. For the v sin i measurements, obtained from spectral synthesis, we estimate an uncertainty of about 2.0 kms(-1). Results. Precise rotational velocities v sin i are presented for a large sample of 100 metal-poor stars, most of them evolving off the main-sequence. For the large majority of the stars composing the present sample, rotational velocities have been measured for the first time.