* China's Liu to visit U.S. this week to sign trade pact-report
* Tesla rival Nio jumps after strong quarterly sales
* Dow Jones on track for worst day in nearly four weeks
* Indexes down: Dow 0.51%, S&P 500 0.50%, Nasdaq 0.83% (Updates to open, adds comments)
By Manas Mishra
Dec 30 (Reuters) - Wall Street's major indexes slipped on Monday as investors booked profits on the penultimate day of the decade after improving global sentiment fueled a U.S. market rally this month.
The announcement of a Phase 1 U.S.-China trade deal earlier in December has partly powered the record-setting run on Wall Street, with the benchmark S&P 500 closing at all-time highs in nine of the past 11 sessions.
Although the finer details of the agreement have not yet been disclosed, the South China Morning Post reported on Monday Chinese Vice Premier Liu He will visit Washington this week to sign the pact.
But with thin trading volumes in a holiday-shortened week, some analysts expect a sideways move before the new year. The Nasdaq snapped an 11-day winning streak on Friday.
"It has been a pretty spectacular year and Q4 especially has been really good so a lot of times people might be inclined to take some profits," said Randy Frederick, vice president of trading and derivatives for Charles Schwab in Austin.
Tech stocks largely led the decline on the S&P, with Microsoft Corp and Apple Inc dragging the sector. The information technology sector is the best performing among the 11 S&P 500 sectors this year.
"It is also not uncommon for the leading sectors to pull back first when people start to sell because if it is an outperformer then it warrants a lot more downside risk," said Frederick.
The Dow Jones Industrial Average was down 144.98 points, or 0.51%, at 28,500.28, the S&P 500 was down 16.11 points, or 0.50%, at 3,223.91 and the Nasdaq Composite was down 74.82 points, or 0.83%, at 8,931.79.
Meanwhile, China's retail sales are expected to have increased 8% in 2019, the official Xinhua News Agency reported, compared with a 9% rise in 2018.
Shares of Nio Inc soared 36.4% after the Tesla rival beat quarterly revenue estimates on higher demand for its electric vehicles.
Declining issues outnumbered advancers for a 1.28-to-1 ratio on the NYSE and for a 1.93-to-1 ratio on the Nasdaq.
The S&P index recorded 12 new 52-week highs and no new low, while the Nasdaq recorded 40 new highs and 13 new lows. (Reporting by Manas Mishra in Bengaluru; Editing by Anil D'Silva and Maju Samuel)