Anomalous temperature dependence of the static spin susceptibility of ${\mathrm{Tl}}_2$${\mathrm{Ba}}_2$${\mathrm{Ca}}_2$${\mathrm{Cu}}_3$${\mathrm{O}}_{10\mathrm{-}\mathrm{\delta }}$ (${\mathit{T}}_{\mathit{c}}$≊125 K) in the normal state

${}_{}{}^{17}{}_{}{}^{}\mathrm{O}$ NMR measurements on triple-layered ${\mathrm{Tl}}_2$${\mathrm{Ba}}_2$${\mathrm{Ca}}_2$${\mathrm{Cu}}_3$${\mathrm{O}}_{10\mathrm{-}\mathrm{\delta }}$ (${\mathit{T}}_{\mathit{c}}$≊125 K) show a virtually identical spin susceptibility for both the pyramidal and square Cu-O planes indicating a strong interlayer coupling and an almost uniform charge distribution in this system. The Knight shift shows a dramatic decrease below ∼150 K, suggestive of spin pairing well above ${\mathit{T}}_{\mathit{c}}$. The nuclear spin-lattice relaxation is Korringa-like. The results are compared with those for (Bi,Pb${)}_2$${\mathrm{Sr}}_2$${\mathrm{Ca}}_2$${\mathrm{Cu}}_3$${\mathrm{O}}_{10\mathrm{-}\mathrm{\delta }}$ (${\mathit{T}}_{\mathit{c}}$≊107 K), which has a similar structure.