The GOP is also vowing to get artists' permission before using musicians' work in future political campaigns.
The apology and pledge were released Tuesday along with an announcement of a settlement with Browne over a federal copyright infringement lawsuit filed in Los Angeles. Browne sued McCain and the national and Ohio Republican parties last year for using his song "Running on Empty" to mock Democrat Barack Obama in a Web ad.
Financial details of the settlement weren't disclosed.
The statement said McCain didn't know about the ad, which was created by the Ohio Republican Party and removed after Browne complained.