* Biotech index up more than 2 pct
* U.S. producer inflation up but underlying trend muted
* Indexes up: Dow 0.3 pct, S&P 0.6 pct, Nasdaq 0.8 pct (Updates to afternoon, changes byline)
By Caroline Valetkevitch
NEW YORK, Nov 18 (Reuters) - U.S. stocks rose in afternoon trading on Tuesday, lifting the S&P 500 to a record high as healthcare shares extended gains.
Actavis Plc, Gilead, Celgene and other biotech names were among the S&P 500's biggest drivers, a day after Allergan agreed to be bought by Actavis. The Nasdaq biotech index was up 2.2 percent.
The S&P health care index was up 1.4 percent, while shares of Actavis were up 7.7 percent, Gilead's rose 2.9 percent and shares of Celgene were up 2.4 percent. Helping Actavis were bullish analyst notes.
Further support for equities came from U.S. producer prices that kept intact a trend of benign inflation.
"Healthcare stocks are doing well, but not as a defensive play, and it is a positive that stock prices are strong and stocks are being used as currency," said Bruce Zaro, chief technical strategist at Bolton Global Asset Management in Boston.
At 1:28 p.m., the Dow Jones industrial average rose 54.61 points, or 0.31 percent, to 17,702.36, the S&P 500 gained 11.74 points, or 0.58 percent, to 2,053.06 and the Nasdaq Composite added 35.18 points, or 0.75 percent, to 4,706.19.
The S&P 500 hit yet another record high, reaching 2,053.26.
The largest percentage decliner on the S&P 500 was Urban Outfitters, down 8.3 percent, a day after reporting results.
Solar company SunEdison rose 24.4 percent to $20.67 as it announced that, together with its unit TerraForm Power , it would buy First Wind for $2.4 billion to enter the U.S. wind power market. TerraForm shares jumped 34 percent to $34.63.
On the Nasdaq 100 the largest gainer was Illumina, which rose 4.6 percent, while the largest decliner was Staples , down 1.5 percent.
Advancing issues outnumbered declining ones on the NYSE by 2,104 to 912, for a 2.31-to-1 ratio; on the Nasdaq, 1,760 issues rose and 899 fell for a 1.96-to-1 ratio.
The S&P 500 was posting 68 new 52-week highs and one new lows; the Nasdaq Composite was recording 86 new highs and 47 new lows. (Additional reporting by Rodrigo Campos; Editing by Nick Zieminski)