NBCUniversal Media LLC has urged Nielsen Holdings to delay the release of Nielsen's Total Content Ratings, saying the company's forthcoming tool to measure audience viewing across all platforms is not ready to go to market, Broadcasting & Cable reported Dec. 15, citing a letter from Linda Yaccarino, NBCU's chairman of advertising sales and client partnerships.

Yaccarino said the measurement tool in its current form still does not have the participation of many digital TV players, and some of its methodologies need to undergo further testing. While she said the industry needs a tool to measure viewing across platforms and NBCU is eager to work with Nielsen to further refine its Total Content Ratings, she strongly urged the company to reconsider the timetable for its release.

In a statement provided to Broadcasting & Cable, Nielsen said Total Content Ratings data will be available for external uses on March 1. The data currently is being given to publishers and agencies "for internal evaluation only," the company said. It also said that Nielsen is continuing to work with a broad range of industry stakeholders to ensure further participation and refinement of the measurement tool.

"We do not underestimate the importance of the rigor of this work, as clients use our metrics to make decisions on content, programming, distribution, and as a currency for ad planning and settlement," the statement said.

NBCU is a unit of Comcast Corp.