Shares of Apple rose only 2.3 percent to $417.80, in midday trading, hours after the iPhone 4S was first handed out to customers worldwide. But the company retained its title as the world's most valuable company, outpacing Exxon Mobil.

The gain in shares of Cupertino, Calif.-based Apple boosted its market capitalization to $387.27 billion, maintaining its status as the world's most-valuable public company. Exxon Mobil, the No. 2, was valued around $378.2 billion in Friday trading.

Apple shares have risen 29.6 percent in 2011 and 38.3 percent in the past year. Fourth-quarter financial results are due to be released Tuesday.

Friday's moderate move brings the total return on Apple shares this year to 29.5 percent, in a year when the S&P 500 has given up 3.3 percent of its value.

Apple shares set an all-time record of $422.86 on Sept. 20, 15 days before the death of Chairman Steve Jobs.

Apple announced Wednesday that it had sold out of the first batch of iPhone4S models, distributed for the first time by Sprint-Nextel, as well as original iPhone carrier AT&T and the more recently added Verizon Communications. Apple's 310 retail stores are also selling the new product.

Long lines of customers were reported at mobile stores in the Eastern U.S., where some had started to line up early Friday. Analysts predict the company may sell as many as 4.4 million iPhones 4s units by Monday.