Business Wire -- Sonic Corp. (NASDAQ: SONC), the nation’s largest chain of drive-in restaurants, today announced that it will host an investor day with industry analysts and institutional investors at the company’s offices on Tuesday, May 12, 2009. The meeting will begin at 8:30 a.m. CDT and conclude at 12:30 p.m. CDT. Presentations addressing Sonic’s business strategies, including marketing, refranchising and operations initiatives, will be simulcast over the Internet. A link to this event may be found at the investor section of the company’s website, www.sonicdrivein.com. A tour of a Sonic Drive-In in Oklahoma City will follow the formal presentations.