Exxon has once again surpassed Apple as the world's most valuable company after the iPhone and iPad maker saw its stock price falter.

Apple Inc.'s stock has been on the decline since the company's quarterly earnings report that was issued Wednesday suggested that its fast growth phase, rare for a company of its size, may be coming to an end.

Apple's stock dropped 2.4 percent to $439.51 in midday trading Friday for a market capitalization of $412.7 billion. That followed a 12 percent drop on Thursday, the biggest one-day percentage drop for the company since 2008. Exxon Mobil Corp. gained 22 cents Friday to $91.57 for a market capitalization of $417.5 billion.

Apple first surpassed Exxon in the summer of 2011, displacing the oil company from a perch it had held since 2005. The two companies traded places through that fall, until Apple surpassed Exxon for good in early 2012 - at least until Friday.

Apple's stock price peaked in September at $705.07 on the day the iPhone 5 was released. Exxon, in the meantime, has been trading steady. Its business - oil - seems less prone to stock market ups and downs than the Cupertino, Calif.-based tech darling.

- The Associated Press