Spectral properties of upper triangular operators $T=(T_{ij})_1\leq i,j\leq n\in B(\mathcal X^n)$, where $\mathcal X^n=\otimes^n_{i=1}\mathcal X_i$ and $\mathcal X_i$ is an infinite dimensional complex Banach space, such that $T_{ii}-\lambda$ has the single-valued extension property, SVEP, for all complex $\lambda$ are studied