THE RISE AND RISE of Apple marked yet another significant milestone last night – when the company, although briefly, officially became the world’s most valuable company.

In a day of mixed trading on Wall Street, the California-based electronics manufacturer temporarily overtook petrol company ExxonMobil – better known on these shores as the parent company of Esso – to become the most valuable company in the world.

At its lowest point yesterday, the oil company shed 4 per cent of its value – while Apple’s shares never fell into the red, closing the day having gained almost 6 per cent.

As a result of ExxonMobil’s temporary decline, Apple’s ‘market capitalisation’ – that is, the total value of all of its shares added together – briefly overtook that of its Texas-based rival.

By the close of business, however, Exxon shares had recovered to gain 2 per cent – pushing its own market capitalisation back to $348.3bn, with Apple’s not far behind on $346.7bn.

Though Apple returned to the number two slot by the end of the day, AP reported that most analysts expected it to eventually pull clear of the oil company and cement its status as the largest company on the planet.

On this day ten years ago – two months before Apple launched the first iPod – Apple’s shares were priced at $9.51 each. Yesterday, they reached a new peak of $374.01 – meaning they are 39 times more valuable than they were a decade ago.

In fact, if you had opted against buying a first-generation iPod and instead spent your $399 buying Apple shares, your investment would now be worth $16,309 – enough to buy an iPad 2 for yourself and 31 friends at today’s prices, with enough change to buy seven iPod shuffles.

The world’s third most valuable company is PetroChina, which is worth $230bn, just ahead of the Industrial and Commercial Bank of China which is worth $225bn based on its current value on the Shanghai exchange.

The most valuable European-based company is BHP Billiton, a mining company, which is worth $172bn.