Emphasising the government's commitment to modernising and expanding PSUs, Prime Minister Manmohan Singh today said his government has no "disinvestment strategy" for state-run units.Laying the foundation stone for a Rs 9,000-crore revival plan for the Indian Iron and Steel Company (IISCO) here, Singh said the government has already provided large amounts for the revival of many PSUs in recent times."There is no disinvestment strategy without examining the viability of the unit," he said. There is an effective system of examining the viablity of each loss-making PSU to identify long-term proposals for rehabilitation and growth, he said.Citing examples, he said, sick PSUs like Bridge and Roof, Heavy Engineering Corporation, Braithwate and Company and Cement Corporation of India have already been provided large amounts for their revival.He said units in West Bengal have been a major beneficiary of the Centre's revival strategy that has put these units on the revival path."IISCO's revival plan is an example where we are exploiting its synergies with SAIL and investing its its future growth," Singh said.