* Losses in Boeing, Caterpillar weigh on industrials
* UTX biggest loser on S&P 500
* Apple dips on threat of import tariffs on iPhones
* Indexes down: Dow 0.27 pct, S&P 0.19 pct, Nasdaq 0.37 pct (Adds comment, updates prices)
By Amy Caren Daniel
Nov 27 (Reuters) - U.S. stocks dipped in choppy trading on Tuesday after President Donald Trump's threat to move ahead with additional tariffs on Chinese goods weighed on industrial stocks.
Trump said he expected to move ahead with raising tariffs on $200 billion in Chinese imports to 25 percent from 10 percent at the start of 2019.
Trump is due to meet Chinese President Xi Jinping at the G20 Summit in Buenos Aires this week, but his latest comments have given little hope about the two countries resolving their trade dispute, which has battered financial markets this year.
The trade-sensitive industrial sector fell 0.97 percent, with Boeing Co, the single largest U.S. exporter to China, down 0.4 percent and Caterpillar Inc 1.3 percent.
United Technologies Corp tumbled 5.8 percent, the most on the benchmark S&P 500 index, after its plan to split into three companies failed to impress investors.
"Until we get more clarification on the trade front, we are going to see some choppy waters," said Ryan Nauman, Market Strategist at Informa Financial Intelligence, Zephyr Cove, Nevada.
Wall Street's main indexes swung between gains and losses during the session, but are currently off their session lows with Apple Inc paring losses and chipmakers turning positive.
The iPhone maker's shares fell as much as 2.1 percent earlier in the session after Trump said tariffs could be placed on the company's laptops and iPhones imported from China. Shares were last down 0.9 percent.
Philadelphia SE Semiconductor index rose 0.16 percent, reversing earlier losses. Maxim Integrated led the gains with a 4.9 percent rise on report that it was set to join the S&P 500.
"A lot of these bounces you see are from significant oversold conditions," said Michael Antonelli, managing director, institutional sales trading at Robert W. Baird in Milwaukee.
At 13:12 a.m. EDT the Dow Jones Industrial Average was down 66.26 points, or 0.27 percent, at 24,573.98, the S&P 500 was down 5.10 points, or 0.19 percent, at 2,668.35 and the Nasdaq Composite was down 25.97 points, or 0.37 percent, at 7,055.88.
Federal Reserve Vice Chairman Richard Clarida said the central bank should continue to gradually raise interest rates, but it is "especially important" to closely monitor new economic data as monetary policy is getting close to a neutral stance.
Fed Chairman Jerome Powell is scheduled to speak on Wednesday and his commentary will be closely watched for further clues on the path of interest rate hikes and the health of the economy in the face of rising trade tensions.
Declining issues outnumbered advancers for a 1.96-to-1 ratio on the NYSE and for a 2.08-to-1 ratio on the Nasdaq.
The S&P index recorded two new 52-week highs and seven new lows, while the Nasdaq recorded 14 new highs and 111 new lows. (Reporting by Amy Caren Daniel in Bengaluru; Editing by Anil D'Silva and Arun Koyyur)