Boston Scientific Corp. made its $25 billion bid for heart devices maker Guidant Corp. official on Sunday, but rival bidder Johnson & Johnson reiterated that it is committed to buying Guidant itself.

Natick, Mass.-based Boston Scientific, which last month indicated it would launch a competing bid for the approved $21 billion deal with J&J, said it would pay $72 a share for Boston Scientific, divided evenly between cash and stock.