Icahn used his official Twitter account to announce the purchase of Talisman shares.
"Disclosed approx 61 million share position in Talisman Energy," his Monday post read. "May have conversations with mgmt re strategic alternatives, board seats, etc."
The Wall Street Journal reported Talisman's overall performance was hit by falling natural gas prices in the United States and issues with an oil platform off the coast of Norway. The billionaire investor spent $277 million to acquire the shares.
There was no formal statement Tuesday from Icahn Enterprises or Talisman Energy.
Icahn Enterprises last month created American Railcar Leasing LLC as a "multibillion-dollar" venture that would have a fleet of 32,500 railcars. It said it expected the railcar business to benefit from "secular changes" in the way in which North American crude oil is delivered.