Marty Martinez, co-founder of the Progressive Democrats of Somerville, who lost a close race to Ward 7 Alderman Robert C. Trane for that seat, announced today he will run for alderman-at-large.

Martinez, who served as the youth services director for former mayor Dorothy A. Kelly Gay, will be the guest speaker at the May 20 contributors meeting of The Somerville News held in the backroom of Davis Square’s Diesel Cafe from 8 to 9 a.m.