The rate coefficient for the reaction O(P-3) + NO2 + M --> NO3 + M (M = N-2), k(1b), was measured over the pressure range 20-800 Torr (N-2) between 220 and 296 K. Pulsed laser photolysis of NO2 at 352 nm was used to produce O atoms and transient long-path diode laser absorption at 662 nm was used to detect NO3 produced in the reaction. The pressure and temperature dependence of the measured rate coefficient is reproduced by the expression k(1b)(T,M) = [k(0)(T)[M]/(1 + (k(0)(T)[M]/k(infinity)(T))]F-c(x), where x = {1 + [log(k(0)(T)[M]/k(infinity)(T))](2)}(-1) and k(0)(T) = k(0)(300) (T/300)(-n), k(infinity)(T) = k(infinity)(300) (T/300)(-m) with k(0) = 3 x 10(-31) cm(6) molecule(-2) s(-1), n = 1.75, k(infinity) = 3.75 x 10(-11) cm(3) molecule(-1) s(-1). m = 0, and F-c = 0.6. This fit does not yield unique values for k(infinity) or k(0) but are presented here merely to obtain k(1b)(T,M) for atmospheric modeling purposes. The reported values are significantly larger than the current recommendation for stratospheric modeling. Our larger values do not significantly increase the role of the title reaction in the Earth's atmosphere in terms of either ozone loss rate or conversion of reactive nitrogen oxides to less reactive forms such as HNO3.