Lockheed Chief Executive Marillyn Hewson told analysts that regulatory reviews have been completed in seven jurisdictions, including the United States, and the sole remaining review in China was expected to conclude without any difficulty.
"With the progress of the regulatory reviews, we now expect to close in the fourth quarter," Hewson said.
Lockheed had previously said it expected to close the deal in late 2015 or early 2016.
United Tech also said it expected the deal to close this quarter.
Hewson said Lockheed also expected to conclude a strategic review of its government and technical services business by the end of the year. She said the company was evaluating multiple options, ranging from a spinoff, a reverse Morris Trust transaction, or a sale of the businesses.
Reporting by Andrea Shalal; Editing by Paul Simao