The Apple (NASDAQ: AAPL) iPhone is not selling up to expectations in the UK. According to the Financial Times, "O2 said shortly before the iPhone's UK launch on November 9 that it expected handset sales of 200,000 in the first two months, but people familiar with the situation said the actual figure for the first eight weeks was about 190,000." But, a number of analysts viewed sales estimates from O2, the exclusive iPhone reseller in the UK to be very conservative. Estimates by research firm Gartner were as high as 400,000.

The reason for the slow sales may be the pricing of the iPhone and its calling plan. The handset plus a minimum contract cost about $1,700.

If the news were in a vacuum it might not sting. But, just a week ago China Mobile (NYSE: CHL) said it had cut off conversations with Apple over distributing the product in China, the world largest cell market. The price of the calling plan Apple wanted to market in the world's most populated nation may be been a sticking point.

If sales in the UK and Europe do not begin to exceed expectations and an Asian roll-out is slow, that leaves the U.S. to carry the burden of Apple hitting its 2008 sales targets.

That may be a little too much to expect.

Douglas A. McIntyre is an editor at 247wallst.com.

Over the past two years, the shares of mobile-phone companies have rallied sharply, both in absolute terms and relative to the S&P 500 index.

Since September 2005, the Dow Jones U.S. Telecommunications Sector -- which has an equivalent exchange-traded fund, the iShares Dow Jones U.S. Telecommunications Sector Index Fund (NYSE: IYZ) -- has gained 40%, outpacing the broad market by more than 21 percentage points.

Despite all the euphoria, a number of recent developments suggest the bullish tide is turning and the sector could be in for a rough ride in the weeks and months ahead.

Consider the following:

Growing competition. Last Friday, BloggingStocks' Douglas McIntyre noted that "an all out price war" brewing in Japan could be a sign of things to come in a saturated U.S. market.