Icahn sees the drugmaker as a possible takeover target, the Journal said. The size of the stake was unclear, the paper reported.

The company's shares spiked as much as 4.8 percent to $57.21 in late-afternoon trading on Tuesday.

Earlier in the day, Bristol-Myers said it added three directors to its board in an agreement with JANA Partners LLC, an activist investor holding less than 1 percent of the company's stock.

(Reporting by Divya Grover in Bengaluru; Editing by Sriraj Kalluvila)