For the fourth year in a row, Apple has continued to climb Fortune's list of the 500 largest companies across the globe. The company first entered the bottom of the ranks at 492nd in 2006, before climbing to 337th last year with $24 billion in revenues. Apple this year ascended to 253rd with over $32 billion in revenue.

Collective earnings for the entire list of 500 companies declined by 85 percent, marking the worst performance since Fortune began keeping track. Profits fell for Fujitsu, Dell and Asustek during their respective fiscal years.

Although a number of companies clearly outpace Apple in terms of sales volume, the Mac maker has managed to sustain ASPs even in the tough market. While HP, Dell and Lenovo have seen a progressive decline in ASPs, with a particular fall-off late in 2008, Apple has kept the average price of its Mac systems hovering around $1,400 for several years. Between 2007 and 2008, analysts observed Mac sales increasing by a record pace while many of its competitors' shipments remained flat.

Google entered the ranks for the first time this year, holding the 423rd position after a 31-percent increase in revenues. The company on Wednesday announced plans to launch its own operating system, Chrome OS. The decision could create a conflict of interest at Apple, as Google's CEO Eric Schmidt currently sits among the Mac maker's board of directors.

Microsoft rose in the Fortune rankings to the 117th spot, with profits up 25-percent over the previous fiscal year. The company recently launched its Bing search engine, designed to compete with Google, while reports suggest an upcoming announcement may relate to a new browser or web-based apps that can run on Google's platform.

Despite the lackluster performance across the board, Apple managed to show a 38-percent increase in profits. HP and Quanta were the only other computer makers to post gains, each up approximately 14-percent, although Apple devices account for a significant portion of Quanta's production.