U.S. television viewers are increasingly turning on the Web, tuning into television and not missing a beat on either, as simultaneous TV and Internet use continues to rise, research firm Nielsen said on Wednesday.

Nielsen said in a report that 57 percent of TV viewers in the U.S. who have Internet access use both mediums at the same time at least once a month. That translates to more than 128 million U.S. consumers.

As the heightened importance of the Web changes the way Americans watch TV, industry executives and marketers are considering ways to adjust their broadcast shows and play into viewers' simultaneous use of the Internet.

"What we're finding is that there's a connection between the two media, and that innovative marketers can take advantage of that," said Gary Holmes, a spokesman for Nielsen.

"One medium can be used to reinforce the other," he said.

Broadcasters can expect some viewers will turn to the Web to learn more about their shows, but they have to be wary of losing the attention of their viewers.

The Nielsen study found the average TV viewer who uses the Internet simultaneously does that for 2 hours and 40 minutes a month, and that 28 percent of the time they are on the Web at home, they are also watching television.

The percentage of time U.S. consumers watch TV and use the Internet simultaneously is about the same as a similar Nielsen study from last year, but the total number of individuals doing that rose because more of them have the Web, Holmes said.

The report also found TV consumption in the United States continues to increase, with the average viewer watching 141 hours per month, a 1.5 percent rise from a year ago.

Holmes said even as viewership of videos on the Internet and on mobile phones increases, Americans still prefer to watch video on their television, as shown by how many more hours they spend in front of the tube.

"The possibility of watching (video) anyplace has really increased dramatically, but really the rule of thumb is that you watch it on the best screen," he said.

by Alex Dobuzinskis