NEW YORK (AFP) -- Apple shares gained $1.31 percent on Wall Street on Monday and the California gadget-maker closed the day with a market capitalization of more than $500 billion.

Apple shares ended the day's trading at $542.44, giving the Cupertino, California-based company a market cap -- the number of shares outstanding multiplied by the stock price -- of $504.01 billion.

The maker of the iPhone, iPad, iPod and Macintosh computer jumped over oil giant ExxonMobil in January to become the largest US company in terms of market value.

Apple dethroned software giant Microsoft in May 2010 to become the largest US technology company in terms of market cap.

Apple stock has risen steadily over the past few years on the release of a string of hit products starting with the iPod in 2001, followed by the iPhone in 2007 and the iPad in 2010.

Apple reported record earnings last quarter, driven by strong sales of the iPhone 4S, which was released a day before the October 5 death of Apple's visionary co-founder Steve Jobs.

Apple's net profit more than doubled in the first quarter of fiscal 2012 to a record $13.06 billion while revenue soared to an all-time high of $46.33 billion from $26.74 billion a year ago.

Apple sent out invitations Tuesday to a March 7 press event expected to be the unveiling of the next generation of the iPad.

The invitations featured a picture of an iPad and the words: "We have something you really have to see. And touch."

The event is to be held at San Francisco's Yerba Buena Center for the Arts, where Apple has unveiled numerous products over the years.

According to the Dow Jones-owned technology blog All Things Digital, the "iPad 3" will be shaped like the current model, but run on a faster computer chip and have improved graphics.

Apple has sold more than 55 million iPads since launching the device in April 2010.