CUPERTINO, Calif., July 24 (UPI) -- Manufacturing problems forced a second delay in the release of a white version of the Apple iPhone 4, the U.S. computing and electronics giant said.

Apple said the white version of the iPhone 4 "continued to be more challenging to manufacture than we originally expected," The Wall Street Journal reported.

The Cupertino, Calif., company didn't explain what the difficulties were in its release issued Friday.

The delay is the second for the white version of the smartphone, and comes a week after Apple Chief Executive Officer Steve Jobs said it would be available by month's end.

The white version was supposed to be released at the same time as the black one, which debuted in five countries on June 24, but now will arrive "later this year," Apple said.

The iPhone 4 has been buffeted by reception issues stemming from its antenna design, which damaged Apple's reputation for product design and quality.

Analysts said the white iPhone 4 delay, likely related to a yellowish tint developing during the device's manufacture, would have little impact on Apple, the Journal said.

Also Friday, Apple began its program to give away cases to iPhone 4 owners to address the reception issue, Macworld reported. Apple said it would provide free cases to anyone who buys the iPhone 4 before Sept. 30. That free case offer includes a choice of either Apple's Bumper or a third-party case. Apple also said it would offer refunds to iPhone 4 users who had already bought Bumpers from Apple.