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New near-infrared observations of NGC6528 are presented. The JHK observationscomplement a previous HST/NICMOS data set by Ortolani et al. (2001), in thatthey sample a larger area, contain a more numerous sample of red giant stars,and include the K band. Also, archival HST data sets (separated by 6.093 years)were used to proper-motion decontaminate the near-infrared sample and extract aclean VJHK catalogue. Using the present wide colour baseline, we compared thecleaned colour-magnitude diagrams of NGC6528 with those of NGC 6553 and NGC104and derived new estimates of reddening and distance, E(B-V)=0.55 and(m-M)o=14.44 (7.7 kpc). Moreover, the morphology and location of the cleanedred giant branch were used to derive a photometric estimate of the clustermetallicity. The average of 10 metallicity indicators yields a mean value of[M/H] ~ 0.0, and [Fe/H] ~-0.20 and +0.08 on the Zinn & West (1984) and Carretta& Gratton (1997) revised metallicity scale, respectively. The best isochronefit to the cleaned K,V-K diagram is obtained for a 12.6 Gyr and Z=0.02isochrone, i.e. the derived metallicity of NGC6528 turns out to be very closeto the mean of stars in the Baade's Window. Five AGB variable star candidates,whose membership has to be confirmed spectroscopically, are bolometrically asbright as the known long period variable stars in NGC6553. As discussed inGuarnieri et al. (1997) for NGC6553, this may indicate that an `intermediateage' population is not needed to account for the brightest stars in externalgalaxies such as M32.Comment: 11 pages, 9 figures, A&A accepte

V, J, H and K imaging of the metal rich globular cluster NGC 6528