Apple is to release the market-ready version of its new operating system – known as a Golden Master – to overseas assemblers in the last week of September, fuelling speculation a new iPhone could be released in early to mid October.

Analyst Ming-Chi Huo has told US sites MacRumours and Apple Insider that the iOS 5 Golden Master is scheduled to be delivered to assembly partners between September 23 and September 30.

If, as rumoured, the operating system’s release is to coincide with the launch of a new iPhone, the device could launch in early to mid October, given a week or two for assemblers to install the software and ship the phones.

Kuo also dropped a few hints about the device itself, saying it will share a lot of the features of the iPhone 4, with 512MB of RAM, a 3.5-inch display, and a glass front and back.