The significant achievement was noted on Thursday by research firm Strategy Analytics. According to Reuters, Apple's iPhone revenue of $11.9 billion surpassed Nokia, which saw its revenue shrink to $9.4 billion.
"With strong volumes and high wholesale prices, the PC vendor has successfully captured revenue leadership of the total handset market in less than four years," analyst Alex Spektor said.
AppleInsider first reported in January that Apple had surpassed Nokia in terms of revenue. Those numbers were based solely on Nokia's Devices & Services division. But the company's total sales, with more than just smartphones, were over $11 billion.
Since then, Nokia's revenue has shrunk even further. Apple, meanwhile, has continued to grow, placing its entire phone business comfortably ahead of Nokia by more than $2 billion.
Apple on Wednesday announced that its quarterly profits increased 95 percent in the second quarter of fiscal 2011, which covers the January through March period. Apple was propelled by sales of 18.65 million iPhones, which grew 113 percent year over year.
iPhone sales for Apple continue to grow at an astronomical rate, as sales this past quarter were the company's best ever. The 18.65 million units sold even bested the previous holiday quarter, in which a then-record 16.2 million iPhones were sold.
While Apple has grown to new heights quarter after quarter, rival Nokia has struggled. The Finnish handset maker ousted its CEO last year, and made Microsoft veteran Stephen Elop its new chief executive.
In his short time at Nokia, Elop has made drastic moves, most notably the decision to abandon the "burning" Symbian platform and instead adopt Microsoft's Windows Phone for its new handsets. Nokia will transition to Microsoft's mobile operating system this year and next, as it moves away from Symbian.
Both Apple and Nokia are also entrenched in a number of lawsuits related to patents. The first shot in the legal battle was fired by Nokia in October 2009, when it accused Apple's iPhone of violating patents related to GSM and wireless LAN technology. It is believed that Nokia's losses in the market prompted the company to sue over the alleged use of 10 patented wireless standards in the iPhone.
Apple responded to Nokia with its own lawsuit, accusing the Finnish company of infringing on 13 iPhone-related patents. The battle of the two smartphone giants is expected to drag out for years, with both companies looking for a court hearing to be held in 2012. The U.S. International Trade Commission -- the group with which the complaints were filed -- has agreed to look into both Nokia's and Apple's complaints against the other.