Apple’s (AAPL) supply partners have reportedly begun production on Retina displays for its 13.3-inch MacBook Pro, according to NPD DisplaySearch analyst Richard Shim. “The supply chain indications are that it’s for a MacBook Pro 13.3 — not a MacBook Air,” Shim said to CNET, adding that the displays are being made by Samsung (005930), LG Display (LPL) and Sharp (SHCAY). All three manufacturers are expected to initially produce a substantially larger number of displays than they did for the current 15.4-inch Retina MacBook Pro. Production for 13.3-inch Retina displays is believed to have begun in the third quarter and the panels are expected to debut this fall in 13-inch MacBook Pro computers.