Time Warner Inc, News Corp and a dozen other top media companies officially announced plans on Thursday to create a coalition to study new ways to measure television audiences.

The long-rumored effort, which will also include CBS Corp, Walt Disney Co and NBC Universal, majority-owned by General Electric Co, comes as TV broadcasters are trying to cope with major shifts in viewing habits, with audiences using the Web and digital video recorders (DVRs) to watch programs at their leisure.

Currently, U.S. audience measurement is dominated by Nielsen Co, which primarily uses a panel of households to estimate how big an audience a particular show or network draws. Those figures are then used to help set advertising rates.

But the consortium, called the Coalition for Innovative Media Measurement, intends to fund a series that will use set-top boxes from cable and satellite companies in hopes of creating a more detailed portrait of TV viewing patterns.

It will also seek ways to better measure how people are watching shows in other formats, like on the Web or on mobile devices, it said.

A number of similar efforts to augment -- or even someday replace -- current audience measurement data are already under way. TiVo Inc, for one, has deals to supply both media companies and ad agencies with detailed data from its digital video recorders.