AOL today reported a better than expected 13% rise in quarterly revenue, helped by higher ad sales.

The company, which is trying to rely less on its declining dial-up subscription service, has turned its focus to reaping more advertising cash from marketers through electronic ad sales.

AOL bought, an electronic trading platform that helps companies advertise on video websites, for $405m last year.

The deal bolstered its efforts to attract more advertisers and publishers to buy and sell advertising through electronic trading desks known on Madison Avenue as "programmatic."

The company, which owns the Huffington Post news website and the TechCrunch blog, reported a 23% rise in advertising revenue in the fourth quarter due to higher sales of premium ad formats, such as video, through its "programmatic" platform.

Revenue from AOL's Third Party Network sales, which includes sales from the "programmatic" platform, rose 63% in the quarter, accounting for a third of total revenue.

The company's total revenue rose to $679m in the fourth quarter to the end of December from $599.5m a year earlier. Analysts on average had expected revenue of $655.8m, according to Thomson Reuters.