IAC/InterActiveCorp, the Internet company founded by Barry Diller, forecast a 2013 operating loss for units that include Newsweek, which it plans to convert to an online-only publication after 80 years of print.

The loss at media and other segments will be $28.2 million to $33.2 million, the New York-based operator of websites such as Ask.com and Match.com said today in a regulatory filing.

While third-quarter revenue almost tripled at IAC’s media unit because it began including its Newsweek Daily Beast unit in its results, the division’s operating loss widened to $13.2 million in the period. IAC announced plans to stop publishing Newsweek as a print magazine last week.

IAC slumped 5 percent to $49.67 at 12:07 p.m. in New York. The stock had gained 26 percent this year before today.

To grow faster than Google Inc., IAC is luring users to its online properties with its own content instead of just links, helping boost queries to websites such as Ask.com by 52 percent in the third quarter from a year earlier. The company, under founder and Chairman Barry Diller, bought About.com from New York Times Co. in September for $300 million to add more information for searches.

Third-quarter net income fell 37 percent to $40.7 million, reduced by a $27.6 million income-tax provision. Earnings per share, excluding the effect of restricted stock units, rose to 71 cents, beating the 66-cent average estimate of 16 analysts, according to data compiled by Bloomberg. Sales climbed 38 percent to $714.5 million.