Marketing specialists who helped package $1.13 billion in Orange County bonds agreed to settle Securities and Exchange Commission charges that they negligently failed to disclose the risk of the investments. The settlement by Jeffrey and David Leifer of San Francisco-based Leifer Capital Inc. is the latest enforcement action stemming from Orange County's financial collapse. The county sought bankruptcy protection in 1994 after sustaining $1.7 billion in losses. The case against the Leifer brothers is the latest in which the SEC cited outside individuals and firms connected with the county's bond offerings. Last week the SEC settled with one of the county's bond counsels on similar charges. Without admitting or denying the charges, the Leifers agreed not to violate securities law in the future under threat of stiffer penalties. There were no financial penalties. The SEC's charges against the Leifers involved their work in preparing official offering statements on seven 1994 bond sales by Orange County, its flood control district and a school district.