Aug 9 (Reuters) - The S&P 500 and the Dow retreated from record highs moments after the open on Monday as energy stocks tumbled on the back of a 4% slump in crude prices. The Dow Jones Industrial Average was down 0.23% at 09:34 a.m. ET after opening higher by 21.16 points, or 0.06%, while the S&P 500 was down 0.08% after rising 0.03% at the opening bell. The Nasdaq Composite gained 0.13% at the opening bell, and was last up 0.10%. (Reporting by Devik Jain in Bengaluru; Editing by Shounak Dasgupta) Our Standards: The Thomson Reuters Trust Principles.