DETROIT — The United Auto Workers membership rose 0.5 percent to 382,513 last year, the union’s highest since 2008 and the third consecutive gain, as U.S. automakers added employees amid rising sales.

The UAW disclosed the 2012 figure, the largest for the union since its membership totaled 431,037 in 2008, in a statement that cited a union filing with the U.S. Labor Department. The union added 1,794 members from 380,719 in 2011.

While the UAW’s 2012 gain followed a 1.1 percent increase in 2011, the union’s total membership is still only about one-fourth its size in 1979, when it peaked at 1.5 million members.

First Published March 30, 2013, 5:39 p.m.