Nielsen Media Research plans to measure how many people actually watch TV commercials starting in November, a move that could result in a decline in advertising rates, The Wall Street Journal said on Tuesday.

Nielsen, which tracks what people watch on television, plans to provide for the first time ratings for TV ads, the Journal said. At the moment Nielsen rates entire television programs, on which TV ads feature.

Both TV networks and advertisers expect Nielsen's new tracking to show viewership drops noticeably when commercials are broadcast during a program, which could fuel advertisers' push for changes in how ads are incorporated into shows.

A drop in viewership could also accelerate the flow of advertising dollars out of television to the Internet and new digital media, the newspaper said.

Nielsen is owned by Dutch media company VNU NV, which was delisted from Euronext Amsterdam on Tuesday as part of its leveraged buyout.