* Dow posts biggest opening bell drop in almost 16 yrs
* Rising bond yields drag as Fed meets, Trump speech eyed
* Health stocks down on Amazon, JPMorgan, Berkshire team-up
* VIX hits highest level since August 2017
* Indexes down: Dow 1.4 pct, S&P 1.05 pct, Nasdaq 0.93 pct (Updates to late afternoon, changes byline)
By Stephen Culp
Jan 30 (Reuters) - U.S. stocks were on track for a second straight day of losses on Tuesday as healthcare stocks and rising bond yields weighed on all three major U.S. indexes.
The Dow Jones Industrial average fell 241 points or 0.91 percent at the opening bell, its biggest opening gap-down in nearly 16 years. The index continued to slide as the trading day wore on.
"People might be profit taking, getting out of the way of a potential sell-off after an extremely strong month," said Jonathan Mackay, investment strategist at Schroders in New York.
U.S. Treasury yields climbed to multi-year highs after the start of the Federal Reserve's two-day meeting, which could shed light on the central bank's economic and rate hike outlook.
Healthcare-related stocks dragged the major indexes down on news that Amazon.com, Berkshire Hathaway and JPMorgan Chase will form a healthcare company with a view to controlling costs for their U.S. employees.
The S&P 500 Healthcare index dropped by 2.1 percent, the biggest loss among the 11 major sectors.
At 2:50 p.m. ET, the Dow Jones Industrial Average fell 366.73 points, or 1.39 percent, to 26,072.75, the S&P 500 lost 29.99 points, or 1.05 percent, to 2,823.54 and the Nasdaq Composite dropped 69.35 points, or 0.93 percent, to 7,397.16.
The CBOE Volatility Index, the closely-watched gauge for investor anxiety, rose to as much as 15.42, its highest level since August. The index was last at 14.88.
MetLife was among worst performers on the S&P 500 following news the U.S. Securities and Exchange Commission was investigating the insurer's failure to pay some workers' pensions. The stock is down 8.8 percent.
UnitedHealth Group was the heaviest drag on the Dow, down 4.3 percent. Pfizer was down 3.4 percent despite its better-than-expected earnings and upbeat 2018 guidance on a lower tax rate.
Harley-Davidson was down 7.8 percent after forecasting a drop in motorcycle shipments this year.
Apple was down 1 percent on fears it would cut production of the iPhone X.
On the earnings front, analysts expect S&P 500 earnings growth of 13.2 percent, up from 12 percent a month ago. Of the companies that have reported, 80 percent showed profit exceeding consensus.
Tonight, U.S. President Donald Trump's first State of the Union address, which is likely to tout the strong economy, will be scrutinized for clues on trade policy and infrastructure spending. Declining issues outnumbered advancing ones on the NYSE by a 4.50-to-1 ratio; on Nasdaq, a 3.15-to-1 ratio favored decliners.
The S&P 500 posted 15 new 52-week highs and 4 new lows; the Nasdaq Composite recorded 38 new highs and 39 new lows. (Reporting by Stephen Culp; Editing by Cynthia Osterman)