A potential $20 billion deal is in the works between the fire-protection company Tyco International PLC and the technology firm Johnson Controls Inc., according to the Wall Street Journal. Johnson Controls CEO Alex Molinaroli would head the combined entity, the newspaper reported.

Johnson Controls, with a market capitalization of $23 billion, is based in Milwaukee. The 130-year-old company invented the first electric room thermostat in 1885, and its current suite of products run the gamut from automotive seats to heating, ventilation and air conditioning equipment to replacement car batteries. The firm’s revenue was down $1.5 billion between 2014 and 2015, with the sore thumb being its automotive interests. Its building-controls segment (mainly climate control) represents the real growth potential, which, presumably, is where a combination with Tyco would bear the ripest fruit.

Tyco, with a market cap of $13 billion, is based in Ireland, and its American operations are headquartered in Princeton, New Jersey. The company provides fire-detection and -suppression services, such as alarms, firefighter equipment and sprinkler systems, to a wide variety of industries. Downturns in some of them, such as the Australian mining industry, led the firm’s earnings per share to fall 28 cents, to $1.44 in its 2015 fiscal year from $1.72 in its 2014 fiscal year.

Both companies have been under pressure to boost their share prices of late, as each has suffered a double-digit percentage decline in the past year.

Johnson Controls will deliver its next quarterly financial report Jan. 28, while Tyco will deliver its own Jan. 29.

A deal between the two firms could be announced as soon as Monday.