By Herbert Lash and Devik Jain Aug 12 (Reuters) - The S&P 500 notched its third straight record high on Thursday, with mega-cap technology stocks taking charge, as investors mulled data showing a steady U.S. jobs market recovery against a backdrop of potentially inflationary producer prices. Energy .SPNY weighed the most and pulled the Dow .DJI from record highs, along with industrials .SPLRCI and materials .SPLRCM, on the heels of a multi-trillion dollar infrastructure bill in the Senate. Micron Technology MU.O dropped 7.1% to the bottom of the S&P 500 after Morgan Stanley downgraded the stock to "equal-weight."