The Alberta government has posted a subsidy offer to pay 12% of construction costs for petrochemical projects that use liquid byproducts of natural gas as raw materials.

No ceilings limit the total value of the Alberta Petrochemicals Incentive Program (APIP) or the sizes of aid candidates. The sole restraints exclude coverage of cost overruns and applying the percentage subsidy only to actual expenses of projects completed under budget.

The sky was the limit in visions of Alberta petrochemical development when provincial Natural Gas Minister Dale Nally and Economy Minister Doug Schweitzer unveiled APIP on Friday.

The announcement recited a C$30 billion ($22.5 billion), 10-year “growth opportunity” forecast to create 90,000 jobs by an Edmonton-area petrochemical and...