Visitors to the top 10 U.S. newspaper Web sites were up 16 percent year-over-year in December, reaching 40.1 million, Nielsen Online announced Tuesday, AFP reported.

The top online newspaper destination in the United States in December was NYTimes.com, The New York Times Web site, with 18.2 million uniques, a 6 percent increase over December 2007, according to Nielsen data. In second place was USA Today (usatoday.com), with 11.4 million uniques, a 15 percent increase; and in third place was The Washington Post (washingtonpost.com), with 9.5 million uniques, a 12 percent increase.

In the fourth and fifth spots were the Los Angeles Times (latimes.com) with 8 million uniques, a 73 percent increase over the same time in 2007, and the Wall Street Journal (WSJ.com) with 7.2 million uniques, a 34 percent rise, according to Nielsen Online, AFP reported.

The only newspaper in the top 10 to lose uniques was The Boston Globe (boston.com), which saw visitor numbers drop to 4.1 million, a 6 percent decrease.

Although readership online is booming, the "challenge for newspaper publishers today is to learn how to capitalise on this active online readership and translate their increasing engagement into revenue," Chuck Schilling, a research director at Nielsen Online, pointed out.

Google sites continued to see the highest visitor numbers on the Internet, with 133.8 million uniques in the United States. Microsoft, meanwhile, had 126 million visitors and Yahoo! had 118 million, according to Nielsen data, AFP reported.