(Reuters) - Johnson Controls Inc (>> Johnson Controls Inc), a U.S. manufacturer of car batteries and heating and ventilation equipment, is in advanced talks to buy fire protection and security company Tyco International Plc (>> Tyco International PLC), people familiar with the matter said.

A deal between Johnson Controls and Tyco, which have market capitalizations of $23 billion and $13 billion respectively, would provide the clearest indication yet that the recent market volatility has not derailed strategic mergers from advancing.

Terms of the potential deal could not immediately be learned. The sources, who asked not to be identified because the negotiations are confidential, cautioned that no agreement was certain. The Wall Street Journal, which first reported on the talks, said a deal could be announced as early as Monday.

Johnson Controls and Tyco did not respond to requests for comment.

The deal would come as Milwaukee, Wisconsin-based Johnson Controls was preparing to spin off its automotive seating and interiors business, to focus on its building efficiency and automotive battery operations.

Johnson Controls' building efficiency segment had sales of $2.9 billion last quarter.

Based in Cork, Ireland, Tyco provides more than 3 million customers globally with fire protection and security products and services.

Tyco was broken up into three companies after turnaround expert Edward Breen took the helm from former Chief Executive Officer Dennis Kozlowski, who was convicted in 2005 of grand larceny, securities fraud and other charges.

Under Breen, Tyco spun off its electronics division, now called TE Connectivity (>> TE Connectivity Ltd), and the healthcare company now named Covidien PLC in 2007. He greatly expanded Tyco's security business with the $1.9 billion acquisition of Broadview Security in 2010.

In 2012, Tyco was broken up into three pieces. The flow-control business, which sells valves and controls for the energy market, merged with Pentair Inc (>> Pentair PLC), while the company's commercial fire and security businesses combined into "New Tyco" and traded under Tyco's symbol. The third piece consisted of the ADT North American residential security business.

Shares of Johnson Controls have fallen by over 26 percent since the start of 2015, while Tyco's shares have fallen by over 30 percent over that period.

(Reporting by Greg Roumeliotis in New York; Additional reporting by Sam Forgione in New York and Ankush Sharma in Bengaluru; Editing by Jonathan Oatis and Peter Cooney)

By Greg Roumeliotis