Standard & Poor's is lowering its long-term sovereign credit rating for Belgium, citing a threat to exports and the country's lack of a permanent government.

In a sign that financial contagion is spreading across Europe, the agency cut Belgium's credit rating from AA+ to AA.

Belgium has been without a permanent government for 530 days, as a series of negotiators has struggled without success to bridge the country's divide between its French-speakers and its Dutch-speakers.

The ratings agency said Friday that "in our opinion, protracted political uncertainty remains a risk to its creditworthiness."

Late Friday, Belgian negotiators hurriedly resumed their stalled efforts to form a government.