Apple said Thursday it would press ahead with mobile software changes that limit tracking for targeted advertising -- a move that has prompted complaints from Facebook and others.

The iPhone maker said updates to its mobile operating system would give users more information and control on the tracking of their online activity by apps on Apple devices.

Apple earlier this year delayed the changes to give online advertisers time to adapt.

But in a letter to the nonprofit group Ranking Digital Rights, Apple said it planned to move forward next year "because we share your concerns about users being tracked without their consent and the bundling and reselling of data by advertising networks and data brokers."

The letter from Apple privacy chief Jane Horvath noted that Apple intends to support online ads but without "unfettered data collection" and noted a split with Facebook, which had expressed concerns about the new policy.

"Facebook and others have a very different approach to targeting," Horvath said in the letter, verified by AFP.

"Not only do they allow the grouping of users into smaller segments, they use detailed data about online browsing activity to target ads. 

"Facebook executives have made clear their intent is to collect as much data as possible across both first and third party products to develop and monetize detailed profiles of their users, and this disregard for user privacy continues to expand to include more of their products."

Facebook responded that Apple was trying to shift attention from the fact that it was collecting more data on its users.

"Apple is being accused of monitoring and tracking people’s private data from their personal computers without their customers’ knowledge through its latest update to macOS - and today’s letter is a distraction from that," the company said in a statement sent to AFP.

"The truth is Apple has expanded its business into advertising and through its upcoming iOS14 changes is trying to move the free internet into paid apps and services where they profit," said Facebook, referring to the latest update to Apple's mobile operating system.

The social media giant said the changes would allow Apple to collect user data while making it nearly impossible for competitors to do so

"They claim it’s about privacy, but it’s about profit," said Facebook.