* Valuations, dollar worry investors as earnings loom
* Donald Trump to hold press conference on Wednesday
* Valeant rises on deal to sell three brands, cancer business
* Dow down 0.2 pct, S&P down 0.06 pct, Nasdaq up 0.01 pct (Updates to open)
By Yashaswini Swamynathan
Jan 10 (Reuters) - The S&P 500 and the Nasdaq were flat on Tuesday morning, while Goldman Sachs led the Dow lower, as investors await the earnings season to test if Wall Street's record levels are justified by corporate earnings in the fourth quarter.
Goldman Sachs fell 1.4 percent after Citigroup downgraded the stock, a move that comes ahead of reports by JPMorgan, Bank of America and Wells Fargo on Friday. JPMorgan was down 0.4 percent, while the other two were flat.
Banks have led a record-breaking run in U.S. equities since Donald Trump's election on Nov. 8. But the rally's momentum has stalled of late as investors now wait to see if he can deliver on his promises of fiscal stimulus.
The U.S. President-elect will hold a news conference on Wednesday, his first since his election.
Wall Street's rally has also led to soaring valuations - the S&P 500 is trading at about 17 times expected earnings, compared to its 10-year average of 14, according to Thomson Reuters Datastream.
"It's the increasing weight of valuation in the market that maybe leading to less enthusiasm in 2017. The dollar is going to be a very important factor for the earnings season," said Stephen Wood, chief market strategist, North America for Russell Investments.
"We expect a choppy, range-bound U.S. equity market until we get more clarity on earnings."
At 9:40 a.m. ET (1440 GMT) the Dow Jones Industrial Average was down 39.38 points, or 0.2 percent, at 19,848, the S&P 500 was down 1.42 points, or 0.06 percent, at 2,267.48 and the Nasdaq Composite was up 0.56 points, or 0.01 percent, at 5,532.37.
The dollar index has risen 4.3 percent since Trump's victory. A strong dollar crimps U.S. companies' revenue from overseas markets.
However, S&P 500 companies overall are set to post their strongest quarterly growth in three years, with earnings estimated to have risen 5.8 percent in the fourth quarter, according to Thomson Reuters I/B/E/S.
Three of the 11 major S&P 500 sectors were flat on Tuesday, while five were lower, led by a 0.6 percent drop in telecom services sector.
A jump in healthcare stocks helped limit losses.
Illumina surged 17.4 percent to $166.17 and was the top boost to the S&P after the diagnostics company gave a strong quarterly forecast and launched a new product.
Valeant jumped 10 percent following a deal to sell its Dendreon cancer business and three skincare brands for about $2.12 billion as the troubled firm looks to pay down its more than $30 billion debt.
Advancing issues outnumbered decliners on the NYSE by 1,502 to 1,063. On the Nasdaq, 1,365 issues rose and 829 fell.
The S&P 500 index showed one new 52-week highs and no new lows, while the Nasdaq recorded 21 new highs and three new lows. (Reporting by Yashaswini Swamynathan in Bengaluru; Editing by Savio D'Souza)