* Nvidia plunges after downgrade
* Nasdaq poised for worst day of February
* Dow up 0.24 pct, S&P 500 up 0.06 pct, Nasdaq down 0.46 pct (Updates to late afternoon, changes byline)
By Chuck Mikolajczak
Feb 23 (Reuters) - U.S. stocks were buoyed on Thursday by gains in the energy sector and a renewed pledge by President Donald Trump to chief executives of major U.S. companies to bring back millions of jobs to the United States.
Trump is expected to introduce a series of proposals that could benefit companies, including tax reforms, a reduction in regulation and increased infrastructure spending that were a part of his election campaign.
Those promises have helped spur equities to record highs, with the S&P 500 up more than 10 percent since the election.
Investors, however, are looking for more clarity on the proposals, which has kept the benchmark S&P index in a tight daily trading range. It has failed to register a move of at least one percent in either direction since Dec. 7.
Trump is scheduled to address a joint session of Congress on Feb. 28.
"The market is willing to hang in there, so to speak, for now, waiting on it," said JJ Kinahan, chief market strategist at TD Ameritrade in Chicago.
"Other than campaign promises, there hasn’t been a whole lot of detail we’ve seen under the new president as far as the market is concerned. I don’t know that you have to come out with full detail but you have to offer something."
The Dow Jones Industrial Average rose 49.65 points, or 0.24 percent, to 20,825.25, the S&P 500 gained 1.53 points, or 0.06 percent, to 2,364.35 and the Nasdaq Composite dropped 26.88 points, or 0.46 percent, to 5,833.74.
Energy, was up 0.6 percent as the best performing of the 11 major S&P sectors as oil prices advanced.
The Nasdaq Composite was on track for its biggest daily percentage drop this month, weighed down by a 9.5-percent drop in Nvidia. BMO cut its rating on the stock to "underperform" and reduced its price target by $15 to $85 per share.
L Brands plunged 15.6 percent to $49.05 as the worst performer on the S&P 500 after the company reported weak sales at Victoria's Secret, its biggest business by revenue.
Boston Scientific lost 2.6 percent after the company recalled its Lotus Valve heart devices, citing reports of problems with the locking mechanism. Shares of rival Edwards Lifesciences rose 4.5 percent.
Advancing issues outnumbered declining ones on the NYSE by a 1.14-to-1 ratio; on Nasdaq, a 1.64-to-1 ratio favored decliners.
The S&P 500 posted 61 new 52-week highs and 2 new lows; the Nasdaq Composite recorded 118 new highs and 34 new lows. (Reporting by Chuck Mikolajczak; Editing by Nick Zieminski)