The rumoured LG Nexus 5 is pegged for release in May but the device may come later due to Google's wavering decision and internal issues.

The brains behind the Google Android operating system which has become the dominant mobile platform Andy Rubin is stepping down as head of that division, the company said on Wednesday.

Google chief Larry Page announced that Sundar Pichai, the head of its Chrome laptop unit, will take over the team in charge of Android software for smartphones and tablet computers.

"Andy's decided it's time to hand over the reins and start a new chapter at Google," Page said, not specifying what Ruben's new post is.

Under Rubin, Android became the leading platform worldwide for smartphones, accounting for some three-fourths of the market, and has become a major force in tablet computers as well.

"While Andy's a really hard act to follow; I know Sundar will do a tremendous job doubling down on Android as we work to push the ecosystem forward."

Pichai is adding Android development to his duties overseeing Chromebooks fielded as a cloud-based alternative to traditional computers, Page said in a blog post.

It was unclear what the leadership change regarding the potential for bringing together Chrome and Android operating systems.

Google has pursued both platforms, with Chrome software designed for laptops that serve essentially as gateways to services hosted in the Internet cloud and Android a popular, and free, engine for powering mobile devices.

The sudden change in leadership may affect the release date of the upcoming version of Android dubbed as the 5.0 Key Lime Pie that will also the delay the device that will carry the new software.

Another reason for the delay is Google's confused mind whether it will pursue its second partnership with LG or release the next Nexus with sister company Motorola. Rumours claimed that the next Nexus smartphone will be Motorola X phone.

The successor of LG Nexus 4 coined as Nexus 5 is rumoured to sport a 5-inch full-HD (1920 x 1080) display translating into a pixel density of 440ppi. The device is also speculated to be equipped with NVIDIA Tegra 4 processor with 2GB of RAM, 8/16GB of internal storage, a 13-megapixel auto-focus rear camera with LED flash and a 3-megapixel front-facing camera.

The smartphone will bear the same affordable price as its predecessor, which is one of the selling points of LG Nexus 4.

The rumoured Nexus 5 will be running the latest Android iteration out of the box, and since the Android 5.0 Key Lime Pie is expected to launch in May at Google I/O, this will be the version underpinning the new flagship smartphone.