We report resistivity and upper critical field B-c2 (T) data for disordered (As-deficient) LaO0.9F0.1 FeAs1-delta in a wide temperature and high field range up to 60 T. These samples exhibit a slightly enhanced superconducting transition at T-c = 28.5 K and a significantly enlarged slope dB(c2/dT) = -5.4 T/K near T-c which contrasts with a flattening of B-c2(T) starting near 23K above 30T. The latter evidences Pauli-limiting behaviour (PLB) with B-c2(0) approximate to 63 T. We compare our results with B-c2 (T)-data from the literature for clean and disordered samples. Whereas clean samples show almost no PLB for fields below 60-70 T, the hitherto unexplained pronounced flattening of B-c2 (T) for applied fields H vertical bar ab observed for several disordered closely related systems is interpreted also as a manifestation of PLB. Consequences are discussed in terms of disorder effects within the frames of (un)conventional superconductivity, respectively. (C) 2009 Published by Elsevier B.V.