Sign up today for the CNBC Sport Newsletter The National Football League on Tuesday approved the sale of 7% of the Las Vegas Raiders by controlling owner Mark Davis to Egon Durban, the co-CEO of Silver Lake, and Michael Meldman, the founder and chairman of Discovery Land Co., at an $11.1 billion valuation, according to a person with firsthand knowledge of the deal who asked not to be named because the transaction is private. The deal includes a 10% "flip tax" the buyers are paying the NFL, the