Darko Tresnjak, who has directed productions at the Old Globe Theater, Williamstown Theater Festival and most recently at Gotham’s Theater for a New Audience, has been named artistic director at Hartford Stage.He succeeds Michael Wilson, who held the post for 13 years and now plans to step up his freelance career (including “The Best Man” on the Rialto next season). Tresnjak’s five-year contract begins in July. He will work at the 48-year-old, 500-seat, single-stage theater alongside managing director Michael Stotts. Yugoslavian-born Tresnjak , who emigrated to the U.S. when he was 10, has made a reputation for himself helming (and sometimes designing) Shakespeare, the classics, opera and well-received revivals of neglected works such as “The Pleasure of His Company” and “Bell, Book and Candle.” He will direct “Bell, Book and Candle” again at Hartford Stage next spring, and will also choose the final selection of the theater’s six-play 2011-12 season. Appointment is the latest in a series of new a.d.’s at leading theaters. Marc Masterson was recently named the a.d. of South Coast Repertory Theater in Costa Mesa, creating an opening at the Actors Theatre of Louisville, while Kwame Kwei-Armah was named to Baltimore’s Centerstage. Tresnjak was artistic director of Old Globe Theater’s Shakespeare Festival for five years, ending in 2009. His productions there included “Coriolanus,” “Hamlet,” “All’s Well That Ends Well,” “The Women” and “Cyrano de Bergerac.” Most recently in Gotham he directed New York’s Theater for a New Audience tour of “The Merchant of Venice” starring F. Murray Abraham. Tresnjak is currently rehearsing “Titus Andronicus” at the Stratford Shakespeare Festival and is also slated to helm a revival of “City of Angels” at Goodspeed Opera House in East Haddam, Conn.