The Media Rating Council has rescinded its accreditation for five Arbitron Portable People Meter markets.

Those markets are: Cleveland, Portland, Ore., Riverside-San Bernadino, Calif., Salt Lake City and Tampa, Fla. The MRC board made the decision based on the recommendation of one of its audit committees because a review of the 2011 Arbitron PPM audits showed “certain issues related to internal controls of the service and declines in service performance metrics.”

Arbitron Senior Manager of Media Relations Kim Myers said that the MRC cited declining response rates in the five markets. The audience research firm is reviewing its processes to improve its performance in terms of panel recruitment and retention, both aimed at beefing up the PPM sample size. Previously-announced efforts to do that, such as using address-based sampling and targeted in-person recruitment, continue.

The MRC doesn’t publicly disclose specifics about its decisions. The group is composed of radio, television, print and Internet companies, as well as advertisers, their agencies and trade associations. The MRC’s goal is to ensure measurement services are valid, reliable and effective.

Ratings services that want MRC accreditation disclose their methodologies to their customers and comply with MRC’s minimum rating standards. They submit to MRC audits designed to authenticate and illuminate their procedures.

Arbitron seeks accreditation from MRC because it’s an industry standard, however the process can take years.

MRC Executive Director/CEO George Ivie stated that Arbitron has continued to work with the MRC in the ongoing audit and accreditation process for PPM markets and that the MRC will continue to monitor and evaluate Arbitron’s progress. “We look forward to a time when these and other unaccredited PPM markets can receive MRC accreditation,” stated Ivie.

With the change, nine of Arbitron’s 48 PPM markets are accredited by the MRC. They are: Atlanta, Cincinnati, Houston, Kansas City, Mo., Milwaukee, Minneapolis, Philadelphia, Phoenix and St. Louis.