Senior management at ONGC and Oil India announced the companies have completed the acquisition of a 10 percent stake in state refiner Indian Oil Corporation (IOC).
The price of the purchase was $873 million, the companies said.
Oil India purchased 5 percent for $440 million, according to Chairman Sunil Kumar Srivastava.
In January, a panel of Indian ministers had approved the 10 percent stake sale in IOC to help the government raise funds to reduce its budget deficit.