Altitum Designer PCB design software can work and convert plenty of different printed circuit formats, including .pcb and .gbp files, and as such is a great option for any PCB related conversion. Used to export a common printed circuit board design to one of the Gerber output files.
Convert Printed circuit board design file to Gerber Bottom Paste Mask output format file.
We found one software available in the database for this conversion.
Microsoft Windows software - convert pcb to gbp on Windows
A PCB and FPGA design software
Convert from pcb file format
The table with program actions contains information about what each program is capable of doing with their files. This may be a good pointer for further searches for certain file conversions and help you find the converter you are looking for if our search result is insufficient for you. However, it is far from perfect and may sometimes show results which are not really usable because of the nature of the software handles the files. So a conversion that appears as possible, just because of matched actions, may in fact not be possible.