In Spring are two American tennis tournaments, each of which likes to be known as the fifth major. Both include both the men's and women's tours at the same time, which does give them the feel of a major, but they have 96 player fields instead of 128, and offer 1000 ranking points to the winners instead of 2000. Still, they're big tournaments.
The Indian Wells Masters, now officially called the BNP Paribas Open, was the Pacific Life Open (with lots of whale ads) from 2002 to 2008, and has had almost a dozen names over the last 38 years. I associate Banque Nationale de Paris and BNP Paribas with the French Open at Roland Garros, but BNP Paribas is now the largest bank in the world, so I guess they can sponsor a tournament anywhere. The Miami Masters, or Sony Ericsson Open, started out many names ago as the Lipton, and is often just called Key Biscayne. Larry Ellis of Oracle now owns the Indian Wells event, and former top ten player Butch Buchholz started the Key Biscayne event.