1502 GMT - Risk premiums on credit assets, or credit spreads, widen as volatility in sovereign bond yields extends to corporate bonds, Societe Generale's Juan Valencia says in a note. Global investment-grade credit and high-yield credit indices have widened since the start of the year, to date, although the moves remain very modest on a daily basis, he says. "We believe that spreads will only stabilize and even rally only when sovereign bonds start to stabilize."