Samsung Electronics will buy SmartThings, a startup that helps connect household devices. The South Korean electronics maker joins Apple and Google in exploring ways to integrate connected household gadgets such as thermostats and lights with mobile apps, a trend known as "Internet of Things."

Samsung did not disclose financials.

SmartThings lets people use a mobile app to control connected devices. The company has some 5,000 developers building devices that connect to its open platform.

Apple in June announced HomeKit, which it describes as a framework to communicate with devices in the home.

Google's Nest has also partnered with companies including Whirlpool and light bulb maker LIFX to integrate their products with its thermostats and smoke detectors.

Samsung has allied with Inte and Dell, while Qualcomm has forged a rival alliance with Microsoft.