* See for data on primary dealers
* Yellen suggests six-month lag between end QE3 and rate hikes
* All 17 respondents see Fed taper done by year-end
* Median expectation is for 0.75 pct fed funds rate by end 2015
March 19 (Reuters) - The Federal Reserve will not begin raising interest rates until the second half of 2015, despite comments from Fed Chair Janet Yellen that suggested increases might come sooner, a survey of top Wall Street economists showed on Wednesday.
Yellen, in a press conference following the end of Wednesday's two-day Fed meeting, said that it would be a "considerable period" between the end of the current bond-buying program and the beginning of interest-rate increases, but then added that it could be "six months or that type of thing."
The markets took the Fed's economic outlook as more hawkish than expected as it pointed to "sufficient underlying strength" in the economy to support an improved jobs market.
The Fed's forecasts showed several committee members see the fed funds rate hitting 1 percent by the end of 2015. Bond yields rose sharply after the statement, and equities followed with their own selloff after Yellen's "six months" remark.
"It is hard to know if Yellen wanted the market (which has taken it hard on the chin following that particular remark) to start thinking of a mid-2015 hike, but that is what was implied by her statement," said Millan Mulraine, deputy head of U.S. research and strategy at TD Securities, who sees rate increases beginning in the fourth quarter of 2015.
However, most dealers did not alter their official views. Ten dealers of 17 polled see the initial rate hikes in the second half of 2015, with another four saying increases would not start until 2016. The Federal Reserve has more than quadrupled its balance sheet to $3 trillion through the purchase of securities in a bid to keep borrowing rates low as the economy recovers.
There are 22 primary dealers, major securities firms entitled to trade directly with the Fed. The 17 respondents expect the monthly bond buying - which was reduced at this meeting to $55 billion - to be wrapped up between September and December.
Yields on interest-rate futures used to gauge the market's expectation for changes in Fed policy rose, raising the chances of a rate increase by July to 78 percent from 64 percent prior to Wednesday's announcement.
The median forecast of the 17 respondents is for a fed funds rate of 0.75 percent at the end of 2015. Of the 12 that have a 2016 forecast, that median is 2.25 percent.
"We're not changing our forecasts just yet, but there is clearly a risk that the Fed hikes earlier than we are forecasting, with their freshened guidance seemingly pointing to rate hikes by next spring," said Derek Holt, vice president of economics at Scotiabank. The bank does not see rate increases happening until the fourth quarter of 2015.
Wednesday's policy statement suggests the Fed will continue to reduce its monthly bond buying program, putting it on target to end in the last months of 2014.
The Fed, as many expected, scrapped its use of a 6.5 percent household unemployment rate as a barrier before raising interest rates. The jobless rate is currently just 6.7 percent and is likely to drop through 6.5 percent before long.
Instead, the Fed will rely on a number of labor-market indicators, inflation figures and "readings on financial developments" to determine when to increase rates.
(Reporting By Richard Leong, Marina Lopes, Luciana Lopez, Karen Brettell, Sam Forgione, Michael Connor and Caroline Valetkevitch; Editing by Andrea Ricci)