Creating a native SQL Server backup file from Netbackup image

Is there a way to create a SQL Server native backup file from a previously taken Netbackup backup image?  We currently backup our SQL Server databases to disk and let Netbackup take them to tape.  We're looking to eliminate the disk drop and backup direct to Netbackup.  Often times we need to send backups of our databases to vendors who require backups in the .bak format. 

In order to be able to use Netbackup for all our SQL Server backups we need to be able to make a .bak file from a previously taken backup.  Is this possible?  I haven't been able to find anything in the documentation suggesting it is, but may just be missing something. 

Thanks in advance for the help.