* Iron ore seen at average $125/tonne in 2013 vs $128 in 2012
* More supply to pressure iron ore prices in second half
* China 2013 iron ore import growth to slow to 5 pct
By Manolo Serapio Jr and Silvia Antonioli
SINGAPORE/NEW YORK, Jan 21 (Reuters) - After 2013 started with a bang for the iron ore market, an increase in global supply is expected to outpace a recovery in demand from top importer China, meaning prices this year may struggle to regain their January peaks, a Reuters poll showed.
A month-long rally in iron ore has lost steam after prices hit 15-month highs this month. And with the economy unlikely to rebound briskly this year, China's raw material demand may not rise sharply enough to suck in more output from global miners such as Rio Tinto .
Benchmark 62-percent grade iron ore .IO62-CNI=SI is forecast to average $125 a tonne this year, according to the median estimate of a Reuters poll of 17 analysts. That is slightly lower than the 2012 average of $128, as analysts predict weaker prices in the second half when supply ramps up.
An aggressive restocking drive by Chinese steel mills lifted iron ore to $158.50 a tonne on Jan. 8, the highest since October 2011. The price has since fallen more than 8 percent, although tight supplies should keep prices high in the first half.
"The next price rise will be real demand-driven," said Macquarie commodity analyst Graeme Train.
"Typically, real demand-driven price increases are much less exciting than restocking-driven price increases."
More stock-building may emerge just ahead of, and after, the Lunar New Year break in February, although the magnitude may not be as strong as in previous years given uncertainty over Chinese steel demand. In February 2011, iron ore surged to a record high near $200, backed by a spike in Chinese steel prices.
The plunge in iron ore prices to three-year lows below $87 in September marked a turning point for the raw material that is the biggest money-spinner for top producers Rio, Vale and BHP Billiton .
Credit Suisse sees little chance of a return to previous cycle peaks.
"For this commodity, the long boom is fading," Credit Suisse said in a report.
Some analysts expect the global iron ore market to be in a surplus starting this year, with new supply coming through in the second half that could pressure prices.
After years of supply being unable to keep pace with demand, Goldman Sachs sees the global market in surplus by 20 million tonnes this year, a figure that it expects to shoot up to 215 million tonnes by 2016.
Indeed, many of the analysts in the poll expect prices to decline progressively over the next two years, resulting in a median estimate of $100 for 2015. The most bearish respondent puts the 2015 average at $75.
But before that happens, iron ore producers will see "one last year of exceptional prices and profit margins in 2013, followed by a transitional year in 2014," said Goldman Sachs, the most bullish among those polled with a forecast $144 average price for iron ore this year.
That is backed by Chinese imports which are forecast to hit a record 778 million tonnes this year, according to the median estimate in the Reuters poll. That is up nearly 5 percent from 2012, although the increase is slower than last year's 8.4 percent rise.
China's crude steel output is forecast at 749 million tonnes, the poll showed, compared with production of 716.5 million tonnes in 2012.
But other analysts doubt China, which supplies more than half of the world's steel supply, can sustain strong steel output. Nomura sees production falling to 700 million tonnes this year and global steel demand growing only 2 percent.
"We expect Chinese steel production to disappoint in the coming years primarily on account of underlying structural issues of fragmentation and over capacity," said Ashraf Khan at Nomura's metals and mining research. (Additional reporting by James Regan in SYDNEY, David Stanway in BEIJING and Ruby Lian in SHANGHAI; Editing by Ed Davies)