The industry’s two top performers’ unions and advertising agencies have recessed talks for a new contract to cover TVand radio commercials. The pact expires March 31; both sides have agreed to return to the table March 11.The Screen Actors Guild and the American Federation of Television & Radio Artists have been negotiating a contract with the Joint Policy Committee of the Assn. of National Advertisers and the American Assn. of Advertising Agencies. Those two groups rep the blurb industry. The talks began Feb. 6.