South Korea surpassed Japan and Sweden to take the top spot in an annual ranking of broadband quality, helped by its government's efforts to boost it as an IT world leader, a study showed on Thursday.

The annual study, conducted by the universities of Oxford and Oviedo and sponsored by Cisco, showed that 62 out of the 66 countries had improved the quality of consumer broadband services since last year.

The role of broadband quality is increasing as future Internet applications -- such as high definition Internet TV or high-quality video communications -- need faster and better connections, the study said.

The top nine countries -- South Korea, Japan, Sweden, Lithuania, Bulgaria, Latvia, The Netherlands, Denmark and Romania -- already have the broadband quality required for such applications, which will become mainstream in three to five years, the study said.

Among other countries ranked for broadband quality, France was 14th, the United States 16th, Russia 18th and Germany 20th. Britain was 31st, China 43rd, Brazil 45th and India 63rd.

Japanese cities led among towns with best quality broadband connections, with Yokohama and Nagoya topping the rankings, ahead of Lithuania's Kaunas.

The countries where cities had the biggest broadband-quality advantage over rural areas were Lithuania, Russia and Latvia.

Only in a few countries did rural areas enjoy better connections than cities. "Sweden is the most successful country in closing the broadband quality gap with residents outside the most populated cities enjoying better quality than those in the cities," the study said.