Shareholders of Pinnacle Entertainment, which owns four casinos in Louisiana, approved a deal Tuesday to sell the company’s real estate assets to a casino property owner. At the special shareholders meeting, which was held at L’Auberge Baton Rouge, Pinnacle stockholders agreed to sell 14 of its 15 casino properties to Gaming and Leisure Properties Inc. Pinnacle would then lease back the casinos for an initial annual rent of $377 million.