An intensification of Spain's recession poses the biggest risk to the country's 'investment grade' credit rating the head of Fitch's sovereign ratings team said on Thursday.

"The biggest threat from our perspective to Spain's investment grade status is actually that the recession there intensifies and that spills into greater concerns about bank asset quality as well as the solvency of the Spanish state," David Riley, said in an interview with Reuters Insider Television.

(Reporting by Marc Jones; Editing by William James)