You can try BeamReader. BeamReader Overview
Or the Premium version of Documents to Go. Documents To Go for BlackBerry Smartphones: Word, Excel and PowerPoint on your BlackBerry Smartphone
Or RepligoReader. http://www.cerience.com/products/reader/blackberry
Note that there are no free options to OPEN a PDF on BlackBerry. Also, I have no idea if those applications are supported in your country.