* Forest Labs surges after Actavis confirms acquisition
* Maker of Candy Crush files for U.S. IPO
* Futures up: Dow 21 pts, S&P 2.5 pts, Nasdaq 4 pts
By Angela Moon
NEW YORK, Feb 18 (Reuters) - Wall Street was set for a flat open on Tuesday after Wall Street posted its biggest weekly gain of the year, as data showed factory activity in New York state slowed this month.
* A New York Federal Reserve gauge of manufacturing was weaker than expected in February after hitting a 20-month high in January.
* U.S. stocks closed higher on Friday, with major indexes notching a second straight week of gains as investors shrugged off some weak economic data that was attributed to bad weather.
* U.S. markets were closed Monday for Presidents Day.
* Shares of Forest Laboratories Inc rocketed more than 35 percent in premarket trading after Actavis said it would acquire the specialty pharmaceuticals company in a massive cash and stock deal valued at about $25 billion.
* Coca-Cola Co reported an 8.3 percent fall in quarterly earnings, hurt by the separation of its bottling operations in Brazil and the Philippines. The stock was down 2.3 percent in premarket trading.
* S&P 500 e-mini futures rose 0.8 point and were in line with fair value, a formula that evaluates pricing by taking into account interest rates, dividends and time to expiration on the contract. Dow Jones industrial average futures rose 5 points and Nasdaq 100 futures added 3.25 points.
* Soros Fund Management, one of the hedge fund industry's most closely watched investors, trimmed its stakes in J.C. Penney and Herbalife late last year, marking a notable shift in course only months after buying into the companies. J.C. Penney shares rose 1.1 percent while Herbalife shares gained 1.5 percent in premarket trade.
* Shares of BlackBerry Ltd rose 4.3 percent in premarket trading after hedge fund manager Dan Loeb's Third Point LLC disclosed a 10-million-share stake in the Canadian telecommunication and wireless equipment company.
* Mobile game maker King Digital Entertainment PLC, best known for the hit puzzle Candy Crush Saga, said it planned to raise up to $500 million in an initial public offering.