SAN FRANCISCO — A federal agency on Wednesday announced an increase in the rates that webcasters such as Pandora Media Inc. have to pay in royalties to music artists to play their songs on free online services.

Pandora Media Inc. and other free webcasting services like iHeartRadio will have to pay 17 cents per 100 song plays, up from the current rate of 14 cents per 100 plays following a ruling from the three judges on the Copyright Royalty Board. Shares for Oakland-based Pandora were up in after hours trading following Wednesday’s announcement.