White still refuses to co-sign the actual paperwork from Gov. Rod Blagojevich that announced Burris' appointment.
But his signature is on a certificate requested by Blagojevich's office Friday. The certificate says a copy of Blagojevich's Dec. 30 appointment letter is "a true and accurate copy of a document setting forth an appointment."
A White spokesman said the certificate just acknowledges the document was filed. A request for the certificate could have been made at any time.
It's not the official U.S. Senate document Democratic leaders want White to sign before Burris can be seated.
U.S. Senate officials are reviewing the certificate and the letter. It remains to be seen whether the certificate from White will be enough to get Burris seated in the Senate.