The Dixie Chicks are the latest in a string of big names to support the ongoing Screen Actors Guild and the American Federation of Television & Radio Artists strike against the producers of commercials over pay and residual rates for actors in ad spots. Variety reports that the trio just turned down a multi-million dollar, one-year endorsement pact with Coca-Cola, because the soft drink behemoth declined to sign an interim agreement with the unions, whose walkout began May 1. (For more news on the Dixie Chicks, see Passages
.) Variety also reports that tennis star Andre Agassi, in support of the strike, has refused an offer to shoot a nonunion ad in Australia following the Summer Olympics. Earlier in the skirmish, Britney Spears canceled a nonunion Clairol shoot, the Backstreet Boys filmed an ad for Burger King under an interim agreement and hip-hop artist Lil' Zane backed out of a proposal by Tommy Hilfiger to star in a nonunion commercial campaign. Spears and 'N Sync also donated part of the proceeds from recent concerts to the SAG Foundation after they had made a nonunion McDonald's commercial that was shot in Canada.