Lockheed Martin, Boeing and Airbus are among the companies that could potentially make first-round bids later this month, sources told the newspaper. A Sikorsky sale could go for about $10 billion, according to the report.
The company's board of directors authorized a review of strategic alternatives for Sikorsky earlier this year.
"As previously announced, UTC is exploring strategic alternatives for Sikorsky, which could include a sale or spinoff. We continue to expect the evaluation will be completed by midyear," a United Technologies spokesman told CNBC in response to the report.
In March, United Technologies CEO Gregory Hayes told CNBC that spinning off the helicopter business would create value. The Sikorsky unit has a roughly 10 percent profit margin, compared to margins of 16 percent for the rest of the business.
"The issue with Sikorsky here is not that Sikorsky is a bad business. Sikorsky is a great helicopter business," he said. "As we think about the portfolio, though, it's really a question of, 'How do you position yourself for above GDP growth, for higher margin into the future?'" he said in the March CNBC "Squawk Box" interview.
United Technologies shares were slightly higher in extended trading Tuesday.
—CNBC's Tom DiChristopher contributed to this report.