reducing font size of programlistings

["Tiru R Bokka" <trb@amplisoft.com>]

Dear friends:

We are writing a book using DocBook 4.2 XML, from which we generate a PDF
document using the tools mentioned a little later in this email.

We are generating the PDF at 12pt by setting body.font.master to 12 (in a
customization layer given in an XSL file). Everything works perfect till
here. 
Now, we have about 20 program listings that would look best if presented on
a single page, but are getting split into multiple pages because of the
larger font size.
How can we specify a different font size just for programlisting elements?

We also want to use a line-height of > 1 (either 1.5 or 1.8) for everything
except these programlistings. What is the best way to accomplish this?

Tools Used:
- docbook-xsl-1.65.1 style sheets
- the latest version of xsltproc (for XML to XSLFO conversion)
(Output of "xsltproc -V":
Using libxml 20611, libxslt 10108 and libexslt 806
xsltproc was compiled against libxml 20611, libxslt 10108 and libexslt 806
libxslt 10108 was compiled against libxml 20611
libexslt 806 was compiled against libxml 20611)
- RenderX XEP 3.8.1 (for XSLFO to PDF conversion)

Please share your insights on this.

Thanks,
-Tiru