* U.S. stocks on track for best performance since 2013
* Trump targets Amazon in call for postal service to hike prices
* Goldman warns of profit hit due to new tax law
* Indexes down: Dow 0.14 pct, S&P 0.11 pct, Nasdaq 0.26 pct (Changes comment, updates prices, adds details)
By Sruthi Shankar
Dec 29 (Reuters) - A slide in Apple and Goldman Sachs' shares pulled Wall Street lower on the last trading day of 2017, in what has been a banner year for U.S. stocks.
Apple declined 0.8 percent after issuing a rare apology for slowing older iPhones with flagging batteries.
Goldman Sachs fell 1.27 percent after the bank said its fourth-quarter earnings would take a $5 billion hit related to the tax overhaul.
"By all accounts we know 2017 has been a great year in the markets," said Arian Vojdani, investment strategist at MV Financial in Bethesda, Maryland.
"The market is rich (in valuation) as of now and if prices and earnings continue to converge, I wouldn't be concerned."
Major U.S. indexes hit a series of record highs in 2017, riding on strong economic growth, solid corporate earnings and low interest rates.
The benchmark S&P 500 has surged 20 percent this year, while the blue-chip Dow has gained more than 25 percent and the tech-heavy Nasdaq about 29 percent. All three indexes are on track for their best performances since 2013.
The market has also shown surprising strength despite tensions in North Korea and political upheavals in Washington. The S&P has closed below 1 percent only four times this year.
Among sectors, the technology index has been the best performer, rising about 37 percent and outpacing gains in the broader S&P index.
Telecom services and energy are the only two sectors to end the year in the red.
The rally is widely expected to extend into 2018, boosted by gains from a new law that lowers the tax burden on U.S. corporations.
At 10:58 a.m. ET (1558 GMT), the Dow Jones Industrial Average was down 34.31 points, or 0.14 percent, at 24,803.2 and the S&P 500 was down 2.85 points, or 0.11 percent, at 2,684.69.
The Nasdaq Composite was down 18.17 points, or 0.26 percent, at 6,931.99.
Seven of the 11 major S&P sectors were higher on Friday, led by 0.35 percent gain in the consumer staples index.
Altria, Coca-Cola and Philip Morris, gained between 0.7 percent and 1 percent in thin holiday trading ahead of the New Year.
Amazon slipped 0.6 percent after President Donald Trump targeted the online retailer in a call for the country's postal service to raise prices of shipments in order to recoup costs.
Declining issues outnumbered advancers on the NYSE by 1,384 to 1,323. On the Nasdaq, 1,453 issues fell and 1,307 advanced. (Reporting by Sruthi Shankar in Bengaluru; Editing by Anil D'Silva)