(Reuters) -Apple ( AAPL ) plans to use a 1.2 trillion parameter artificial intelligence model developed by Google to help power an overhaul of the Siri voice assistant, Bloomberg News reported on Wednesday.

After an extensive evaluation, the companies are finalizing a deal that would have Apple ( AAPL ) pay about $1 billion a year for access to Google's technology, the report said.

The iPhone maker will use Google's Gemini model as a stopgap until its own systems are ready, Bloomberg said. The model's 1.2 trillion parameters, a measure of AI model complexity, would dwarf Apple's ( AAPL ) current systems.

Apple ( AAPL ) and Alphabet did not immediately respond to Reuters requests for comment.