Apple's much-delayed and "challenging" white iPhone 4 could finally hit shelves in Spring 2011.

Mac enthusiast site 9to5 Mac has uncovered US Apple Store sinage that states: "The white iPhone will be available Spring 2011."

The delay could see the white phone released just months before a new 'iPhone 5' is launched.

In July this year Apple sent out a press release when the white iPhone 4 failed to appear as promised: "White models of Apple’s new iPhone 4 have continued to be more challenging to manufacture than we originally expected, and as a result they will not be available until later this year. The availability of the more popular iPhone 4 black models is not affected."

Billed as the thinnest smartphone ever, Apple introduced the iPhone 4 in June 2010, adding FaceTime video calling, Retina Display, 5 Megapixel camera and HD Video recording to the iconic smartphone.

9to5 Mac

[Via 9to5 Mac]