* Dow Chemical to spin off unit, merge it with Olin
* Healthcare buoys indexes as biotechs bounce back
* Fed Chair Janet Yellen to speak shortly before the closing bell
* Indexes: Dow flat, S&P up 0.1 pct, Nasdaq up 0.3 pct (Updates prices, adds GDP data, comment)
By Rodrigo Campos
NEW YORK, March 27 (Reuters) - U.S. stocks edged up on Friday, with major indexes trying to avoid falling every day this week, ahead of a speech by Federal Reserve Chair Janet Yellen that could make for a volatile close on Wall Street.
Healthcare stocks helped buoy indexes with biotech stocks up 1.6 percent following four sessions of losses, while energy weighed the most on the S&P 500 as crude prices resumed their decline.
Fed Chair Yellen will speak on monetary policy in San Francisco, just 15 minutes before the closing bell (1945 GMT), and traders will keep an ear out for clues on the timing of the start of the tightening path at the Fed.
Equities have traded in lock step with the U.S. currency of late ahead of the start of earnings season, as traders gauge how much the greenback's strength will hurt corporations' bottom lines.
"Yellen will be the big news of the day, certainly, so I don't expect a lot of movement before that," said Peter Jankovskis, co-chief investment officer at OakBrook Investments LLC in Lisle, Illinois.
"We'll see how people interpret what she has to say."
At 10:11 a.m. EDT (1411 GMT), the Dow Jones industrial average fell 3.37 points, or 0.02 percent, to 17,674.86, the S&P 500 gained 2.2 points, or 0.11 percent, to 2,058.35 and the Nasdaq Composite added 15.65 points, or 0.32 percent, to 4,879.02.
Dow Chemical shares rose 3.7 percent to $48.16 after it announced the spinoff of part of a unit that will then merge with Olin Corp. Olin shares soared 21 percent to $32.90.
BlackBerry posted a fiscal fourth-quarter profit, its turnaround efforts beginning to gain traction. BlackBerry shares were up 2.5 percent at $9.53 in volatile trading.
U.S. consumer sentiment fell month-over-month in March, a survey released on Friday showed, though the decline was smaller than forecast.
The final reading on gross domestic product for the last quarter of 2014 was unchanged from the previous forecast, at a 2.2 percent rate of expansion. After-tax corporate profits fell at a 1.6 percent rate in the fourth quarter as a strong dollar dented the earnings of multinationals.
Advancing issues outnumbered declining ones on the NYSE by 1,602 to 1,177, for a 1.36-to-1 ratio; on the Nasdaq, 1,289 issues rose and 1,061 fell, for a 1.21-to-1 ratio.
The S&P 500 was posting 2 new 52-week highs and 5 new lows; the Nasdaq Composite was recording 16 new highs and 19 new lows.
Reporting by Rodrigo Campos; Editing by Chizu Nomiyama and Nick Zieminski