* White House says to lead efforts on tax reforms
* Fed Chair Janet Yellen to speak later in the day
* Tesla up after China's Tencent takes 5 pct passive stake
* Futures down: Dow 27 pts, S&P 3.25 opts, Nasdaq 5.75 pts (Adds details, comments, updates prices)
By Yashaswini Swamynathan
March 28 (Reuters) - U.S. stocks looked set to open slightly lower on Tuesday as investors assessed President Donald Trump's first major policy stumble, while awaiting comments from several Federal Reserve officials, including Fed Chair Janet Yellen.
Volatility spiked, while demand for risk assets fell after Republicans were forced to withdraw a bill to reform the American healthcare system on Friday.
However, stocks pared most of their losses to end slightly lower on Monday as investors focused on Trump's promise to lower taxes - a key driver of the record-setting rally on Wall Street after the November election.
The White House said late Monday it would take a lead role in crafting legislation to reform the U.S. tax code, with an August target date.
"Yesterday's move was actually quite a small unwind and was quickly opposed and it tells me that investor sentiment hasn't been unduly damaged by the failure of that legislation," said James Athey, Investment Manager at Aberdeen Asset Management.
"We would see this volatility to be normal and healthy and not something to be overly concerned about at this stage."
Investors are eyeing Federal Reserve Chair Janet Yellen's speech at a conference in Washington later in the day, where she could provide some insight into the timing of the central bank's next interest rate hike.
Other Fed officials scheduled to speak at separate events include Fed Board Governor Jerome Powell, Dallas Fed President Robert Kaplan and his Kansas City counterpart, Esther George.
Dow e-minis were down 27 points, or 0.13 percent, with 21,077 contracts changing hands.
S&P 500 e-minis were down 3.25 points, or 0.14 percent, with 128,985 contracts traded.
Nasdaq 100 e-minis were down 5.75 points, or 0.11 percent, on volume of 23,278 contracts.
The Conference Board will issue a report, which is likely to show consumer confidence at 114.0 in March, slightly below 114.8 in February. The data is due at 10:00 a.m. ET (1600 GMT).
Shares of Tesla rose 2.1 percent to $275.86 in premarket trading after the maker of electric cars said Chinese technology giant Tencent Holdings had paid $1.78 billion for a 5 percent passive stake in the company.
Ford rose 0.8 percent to $11.55 after Trump tweeted that the U.S. automaker would make a major announcement regarding three plants in Michigan.
Red Hat was up 4.7 percent at $86.10 after the Linux operating system distributor reported quarterly revenue that beat analysts' expectations. (Reporting by Yashaswini Swamynathan in Bengaluru; Editing by Anil D'Silva)