Petróleos Mexicanos within weeks will unveil "Project Phoenix" -- a $2.5-billion plan that aims to boost Mexico's petrochemical industry after years of neglect, Raul Muñoz, director-general of the state-owned company, said Tuesday. Formal invitations would be extended next month to potential investors in the first of two complexes that will constitute the plan, he said. Muñoz offered no additional details Tuesday, but industry sources say the project continues to change form as Pemex works it out in consultation with potential investors.