Apple has pulled Nest’s internet-connected thermostats and smoke detectors from sale at its US stores.
The BBC understands the technology company removed the products as part of a wider switch to only promote smart home devices compatible with its own HomeKit platform.
However, Apple continues to sell the Thermostat in the UK and across Europe.
Nest is owned by Google, which is developing rival technologies to link “internet of things” kit together.
The search firm announced in May that it was working on Weave – a library of common commands – and Brillo – an Android-based operating system for IoT machines.
For now, Nest’s Thermostat and Protect products can be controlled via its own iPhone or Android app. The division also promotes its own “Works with Nest” programme, which allows third-party products to communicate with the devices.
Mercedes, LG, Whirlpool and Philips are among firms that have taken advantage of the access this grants to Nest’s application programme interfaces (APIs) – the code that controls how different software programmes interact with each other.
By contrast, Apple is promoting HomeKit – its own platform that lets users control and co-ordinate the use of smart home devices via its voice-activated virtual assistant Siri.
The firm requires accessory makers to prove they have adopted a tough encryption standards before it will certify them, and has designed the system to limit the collection of data about who used what and when.
“HomeKit introduces a new way for you to control supported devices in your home… and we’ve taken great care to make sure that the convenience this enables doesn’t come at the expense of your privacy,” the firm’s website states.
The first products to support the standard began going on sale recently, including a thermostat made by Ecobee and a light dimmer switch from Lutron.
A spokesman for Apple declined to comment about its US sales restrictions, which was first reported by Mashable.
But in an interview before the ban, Nest’s chief executive told the BBC he was confident his firm was already doing enough to protect people’s privacy.
“We’re taking very much a cross-platform approach,” said Tony Fadell.
“Through the Works with Nest programme and the protocols that we use inside, it’s going to be a very robust thing.
“At the end of the day though, customers do not buy platforms, they buy products first and foremost.
“So, anybody who is selling a product-like platform or trying to convert you on a platform, they’re not going to be successful because that’s not where customers start.”
Read more of Tony Fadell’s interview with the BBC