A new report from Taiwan-based publication DigiTimes poses a troubling claim that Apple is facing supply shortages overseas. This means that iPhone 4S shipments will be allegedly slowed for the fourth holiday quarter of 2011.

The iPhone 4S has been called the most successful product launch ever for many carriers, with lines continuing to form around the world for the new handset. Will Apple be able to meet demand?

DigiTimes reports:

Apple has informed upstream suppliers of parts and components for iPhone 4S to delay part of their shipments for the fourth quarter of 2011 to the first quarter of 2012 as sales of the iPhone 4S have not been as strong as those concluded in the pre-sales period and also due to shortages in the supply of some key components, according to sources at the iPhone 4 supply chain.

According to a Chinese-language Commercial Times report, Apple is likely to adjust downward its shipments of iPhones and iPads from related suppliers by 10-15% in the fourth quarter.

The part of the report that says “sales of the iPhone 4S have not been as strong as those concluded in the pre-sales period” seems to fly in the face of every other report that Apple is seeing incredible sales of the smartphone. Apple announced a record-breaking 4 million units sold over launch weekend.

Component shortages seem like a much more likely reason for delayed shipments in the coming weeks. Apple may literally not be able to make handsets fast enough, and a report from yesterday already pointed out that Apple is prioritizing its own retail stores with iPhone 4S supply. Retailers everywhere seem to be running low on stock.

Hopefully Apple won’t miss out on holiday sales due to supply shortages overseas.