Amazon.com Inc., Apple Inc. and Alphabet Inc.'s Google are partnering to lay the groundwork for better compatibility among their smart home products, the companies said on Wednesday.

Zigbee Alliance, whose members include IKEA and NXP Semiconductors among others, will also contribute to the project, titled "Connected Home over IP."

The rare partnership comes against the backdrop of an intensified competition among global technology companies to dominate the market for voice assistants and other smart devices.

The group aims to make it easier for device manufacturers to build products that are compatible with smart home and voice services such as Alexa, Siri and Google Assistant.

Earlier this year, another consortium led by Amazon had launched an initiative to let users access Alexa, Microsoft Corp.'s Cortana and other voice-controlled virtual assistant services from a single device.