The company is in talks with two-three firms, including stranded projects of private companies, and they are at advance stages, said the source.
"NTPC is likely to acquire 3,000-4,000 MW power plant. The deal may be announced in two-three months," he said, adding that it will acquire the project on 70:30 debt equity ratio.
Country's largest thermal power producer NTPC had said in January that it has identified 7-8 private power projects as potential acquisition targets and will take a final call on them before end of FY'15.
The criteria for selecting the project would be based on the availability of coal linkage, environmental clearance, land and water available to the plant and it should also have a PPA (power purchase agreement) in place.
NTPC is reportedly in talks with private power companies like L&T and Shapoorji Pallonji Group for taking over their stranded plants.
The state-owned generation firm aims to add 14,000 MW capacity by 2017. Its current installed capacity is 43,143 MW.