The expanded National Library of China in Beijing as seen in a September 5, 2008 photo. [China Foto Press]

The National Library of China became the world's third-largest library on Tuesday following the opening of a newly expanded area, Xinhua news agency reports.

The second phase of the Beijing library added 2,900 more seats and extended the floor total area to 250,000 square meters. The expanded library now ranks behind only the U.S. Library of Congress and the Russian State Library in terms of size, Xinhua says.

Technology is the highlight of the second phase. Machines provide round-the-clock book return service and every corner is covered by a Wi-Fi network. Readers can bring their own laptops or use the 560 computers available at the library.

A digital section provides audio materials for visually-challenged visitors, who can browse the selection with voice-controlled computers.