PMM, for the PGWP extension, you need an LMO but the employer need not show recruitment/advertisement efforts.
Read this!!!
"In cases where the employer is making a permanent job offer to employees who have completed the PGWPP for employment in a skilled occupation (within National Occupational Classification 0, A and B codes only), the employer will not be required to demonstrate recruitment efforts. It is recommended that the employer submit the application for an LMO approximately four months before the expiry of the Post-Graduation Work Permit."
http://www.hrsdc.gc.ca/eng/workplaceskills/foreign_workers/intstugrad.shtml
Hope this helps.