(Reuters) – Oracle Corp is in talks with Micros Systems Inc to buy the software maker for retailers and hotel chains for more than $5 billion, Bloomberg reported, citing people familiar with the matter. While the companies are in exclusive talks, they could still fail to reach an agreement, the report said. (http://r.reuters.com/hyw22w) Micros shares were up 17 percent at $67.54 in early afternoon trading on the Nasdaq. Oracle shares were up 1 percent at $42.53. Oracle and Micros could not be immediately reached for comment. (Reporting by Supantha Mukherjee in Bangalore; Editing by Ted Kerr)