Yahoo! Inc. is rolling out 18 new series in a digital video push, stepping up its efforts to woo marketers and consumers with premium content.The new offerings from the Web portal will bring its total to 55 series, the company said Monday during a presentation in New York. The new content includes original programming, live broadcasts and videos for its magazines that are focused on subjects such as cars and food.

Chief Executive Officer Marissa Mayer, who has run Yahoo since 2012, is counting on video to help drive a turnaround at the Web portal, which has struggled against rivals such as Google Inc. and Facebook Inc. Yahoo’s new line of businesses including video increased revenue 58 percent during the first quarter compared with 8 percent total revenue.

“You’ve been talking, and we’ve been listening,” Lisa Utzschneider, senior vice president, said during the gathering for advertising executives. “You want premium content and the ability to connect with a loyal and engaged audience.”

The new programming includes “Ultimate DJ,” an electronic music competition-style live series with Simon Cowell as executive producer, and “The Pursuit,” a scripted original long-form series from film producer Scott Stuber and Beth McCarthy Miller, a former director of “Saturday Night Live.” There are multiple new programs from Yahoo’s magazine platforms, including “I Am Naomi,” starring model Naomi Campbell.

Yahoo’s finance and news properties also will start new live shows, Kathy Savitt, the company’s chief marketing officer, said during the presentation. Katie Couric, the company’s global anchor, introduced a new daily live broadcast.

Yahoo has been adding premium content to its video lineup, including the show “Community,” which had formerly been on NBC and stars Joel McHale, and “Sin City Saints,” an original program about a Las Vegas basketball franchise.