Google Inc. said Tuesday that its chief financial officer, George Reyes, will retire by the end of the year, creating the highest-ranking job opening at the Internet search leader since it went public three years ago. Reyes has been at Google since 2002 and will stay on the job while he helps the Mountain View-based company find his successor. The transition is expected to be completed before January. In a statement announcing his decision, Reyes, 53, didn"t say why he decided to retire. "Working at Google these past 5 1/2 years has been an extraordinary ride," Reyes said. "I"m honored and flattered to have been a part of this great management team. I know I"m leaving the company in good hands with a remarkable team of professionals that will continue to build on Google"s tremendous achievements."