  The aim of the present work is to determine accurate metallicities for a
group of red giant branch stars in the field of the bulge Globular Cluster NGC
6441. This is the third paper of a series resulting from a large project aimed
at determining the extent of the Na-O anticorrelation among Globular Cluster
stars and exploring its relationship with HB morphology. We present an LTE
abundance analysis of these objects, based on data gathered with the FLAMES
fiber facility and the UVES spectrograph at VLT2. Five of the thirteen stars
observed are members of the cluster. The average Fe abundance for these five
stars is [Fe/H]=$-0.39\pm 0.04\pm 0.05$~dex, where the first error bar includes
the uncertainties related to star-to-star random errors, and the second one the
systematic effects related to the various assumptions made in the analysis.The
overall abundance pattern is quite typical of Globular Clusters, with an excess
of the $\alpha-$elements and of Eu. There is evidence that the stars of NGC
6441 are enriched in Na and Al, while they have been depleted of O and Mg, due
to H-burning at high temperatures, in analogy with extensive observations for
other Globular Clusters: in particular, one star is clearly Na and Al-rich and
O and Mg-poor. We obtained also quite high V abundances, but it is possible
that this is an artifact of the analysis, since similar large V abundances are
derived also for the field stars. These last are all more metal-rich than NGC
6441 and probably belong to the bulge population.
