Taiwan-based information technology publisher DigiTimes is reporting that its supply chain sources say Apple is ordering a massive downward revision of its iPad shipping estimates for the remainder of 2013.

The site says that Apple's initial estimate of 60 million iPads to be shipped has been revised to 33 million units. The report, authored by Rebecca Ko and Alex Wolfgram, lays the blame for the revision at the feet of the iPad Mini, which is expected to ship 15 million more units than initially expected.  

According to the report, Apple is set to ship 88 million iPads in 2013, as opposed to its original 100 million units expectation.  

Wolfgram also writes that Apple's main supplier of touch sensors for the iPad may not have the production capacity to meet Apple's demand for the next-generation iPad products. Apple is expected to use the same touch-screen components across the various iPad lines in upcoming releases.

This is not the first time Apple has been rumored to have iPad supply chain issues. In October, Digitimes reported that recent market entries by the likes of Microsoft and Samsung, combined with a fire at a chemical plant in Japan led to diminished supplies of touch screens.  

The DigiTimes report comes one day after BusinessInsider.com reported Citi went bear on Apple with its report that echoes earlier speculation of the iPad Mini eating into sales of the iPad. Citi, in fact, is expecting sales of all iPad models to flatten in 2013.

Investors have long fretted that the iPad Mini would cannibalize sales of the larger iPad, which retails for $170 more and carries heftier margins. Consumer trends are pointing towards smaller devices like the iPad Mini over larger tablets like the iPad, and Apple appears to be trying to get ahead of consumer whims.

The question is, will supply concerns lead investors to continue their bearish run on the company's stock? As late as September, Apple's shares were selling at $705. Monday Apple's shares closed below $419.