Shares of Spanish-language radio broadcaster Entravision Communications rose after audience measurement firm Arbitron Inc. said it would delay implementation of its new Portable People Meter system in key markets.

Originally, Arbitron planned a switch to the new measurement system in March 2008 for nine markets, including Los Angeles. After broadcasters complained, however, the company postponed the switch until September 2008 while it conducts additional research to hone the system.

Entravision believes the new system will undercount minority viewers, lowering its ad revenue. The company owns 48 television stations and 47 radio stations, mostly affiliated with networks run by Univision Communications.

Entravision jumped 68 cents to $8.13 per share in morning trading on the New York Stock Exchange.