Oct 26 (Reuters) - The S&P 500 and the Dow opened at record highs on Tuesday, helped by upbeat results from companies including United Parcel Service, while investor focus turned towards results from Microsoft and Alphabet later in the day. The Dow Jones Industrial Average rose 49.90 points, or 0.14%, at the open to 35,791.05. The S&P 500 opened higher by 12.21 points, or 0.27%, at 4,578.69, while the Nasdaq Composite gained 90.80 points, or 0.60%, to 15,317.50 at the opening bell. (Reporting by Devik Jain in Bengaluru; Editing by Maju Samuel)