Does an appeal of a third-party proceeding ancillary to a criminal forfeiture action have to be treated as a "civil" or "criminal" appeal?

We are presented with the issue whether an appeal of a third-party proceeding ancillary to a criminal forfeiture action should be treated as a "civil" or "criminal" case for purposes of determining the deadline to file a petition for panel rehearing or rehearing en banc under Federal Rule of Appellate Procedure 40(a). In a similar context, we have held that for purposes of determining the timeliness of an appeal related to a third-party petition to amend a criminal forfeiture order, the third-party proceeding will be considered "civil in nature." United States v. Alcaraz-Garcia , 79 F.3d 769, 772 n.4 (9th Cir. 1996). We see no reason to depart from that approach in this context. We therefore hold that an appeal from a third-party proceeding ancillary to a criminal forfeiture action should be treated as a civil appeal for purposes of applying Rule 40(a).