Bono stands to make a lot of money from the Facebook IPO - possibly enough to make him the world's richest musician.

The U2 front man is a partner in Elevation Partners, a private equity firm that owns a little more than 2 percent of Facebook. Elevation's stake in Facebook is valued around $1.3 billion, after putting in about $176 million.

According to SEC filings by Facebook, Elevation Partners is selling about 4.6 million shares of Facebook in the IPO. That will leave it with a total of 35,487,149 Class B shares, or 2.4 percent of the total. It also gives the private equity firm 2.3 percent of voting rights (Class B shares are different because they entitle the owner to 10 times more votes than a Class A shareholder.)  

Whether or not that makes Bono richer than current number one Paul McCartney, who is worth $1.05 billion according to MTV News, is uncertain. Elevation Partners, based in San Francisco with a secondary office in New York, is a privately-held company and isn't under any obligation to disclose Bono's stake in it.

Earlier reports had Bono's net worth pegged at $900 million after a 30-year music career. The 2011 world tour by U2 was the highest-grossing of the year, with receipts of more than $300 million.