We report on the finding of a 153-day periodicity in the magnetic field strength and solar wind speed measured at 1 AU during the years 1978--1982. The period and the occurrence epoch are consistent with the 154-day periodicity previously reported for events occurring at the Sun. In particular, the variations in the field strength and the occurrence rate of energetic (tens of MeV) solar particle events are in phase. The similar periodicities in the interplanetary field and solar phenomena are consistent with a global phenomenon. Whereas this periodicity is quite strong for the magnetic field magnitude, there is only a weak periodicity for the individual field components. The field magnitude shows essentially no periodicity at this period during the previous and following solar maxima. The lack of persistence, and of significant harmonic components of the observed periodicity, does not support the proposal of a solar clock mechanism. The most significant variations in the complete near-earth magnetic field data base (1963--1997) with periods of less than 200 days occur at 166 and 146 days. ¿ 1998 American Geophysical Union