* Iron ore has rebounded nearly 4 pct from 4-month lows     * Gains also spurred by rising billet prices     * Iron ore stockpiles in China top 100 mln tonnes      By Manolo Serapio Jr     SINGAPORE, Feb 18 (Reuters) - Spot iron ore prices rose further away from last week's seven-month lows as traders bet on more price increases and Chinese steel mills replenished inventories.     Recent sharp gains in the price of spot steel billet in China, suggesting demand in the world's top steel consumer is on the mend, have fueled gains for iron ore. But plentiful spot supplies and rising stockpiles of the raw material across Chinese ports could temper further price increases.     Iron ore for immediate delivery to China  
  .IO62-CNI=SI
   climbed nearly 1 percent to $124.40 a tonne on Monday, according to data compiler Steel Index, rising for a fourth straight day.     Buying interest for spot iron ore cargoes picked up after the price fell to $120 on Feb. 11, the lowest since July 2 lats year. Buyers took their cue from rising prices of spot billet in the main Tangshan area, which have rebounded to 2,920 yuan ($480) a tonne on Monday from a low of 2,790 yuan earlier this month.     "Traders and producers are expecting even better (iron ore) prices in coming weeks as construction activity in China gradually picks up," Australia and New Zealand Banking Group said in a note.     Shanghai steel futures rose for a fourth consecutive session on Tuesday, although the increase was a fraction of Monday's 1.4 percent jump. The most-traded rebar for May delivery on the Shanghai Futures Exchange  
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   was up 0.1 percent at 3,442 yuan a tonne by midday.     More market participants were back this week after the Lunar New Year break in China, but some think the price rally may be short-lived.     "The buying interest is not that strong and there's still a lot of supply in the market," said a trader in Shanghai.     "While there's a lot of movement in seaborne prices, the prices of port stocks have not changed much."     Top miner Vale  
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   is holding another tender on Tuesday for a 144,000-tonne shipment of Brazilian Carajas iron ore fines with iron content of 63.88 percent, traders said.     Stockpiles of imported iron ore at China's 34 major ports rose to a record 100.86 million tonnes as of Feb. 14, up almost 5 million tonnes from the previous week, according to local Chinese media.  
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       At the Dalian Commodity Exchange, iron ore for delivery in May  
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   was steady at 868 yuan a tonne after a three-day runup.       Shanghai rebar futures and iron ore indexes at 0406 GMT                                                                                                          Contract                          Last    Change   Pct Change   SHFE REBAR MAY4                   3442     +4.00        +0.12   DALIAN IRON ORE MAY4               868     +0.00        +0.00   THE STEEL INDEX 62 PCT INDEX     124.4     +1.20        +0.97   METAL BULLETIN INDEX            124.69     +2.76        +2.26   Dalian iron ore and Shanghai rebar in yuan/tonne   Index in dollars/tonne, show close for the previous trading day  ($1 = 6.0641 Chinese yuan)   (Reporting by Manolo Serapio Jr.; Editing by Richard Pullin)  ((manolo.serapio@thomsonreuters.com)(+65 6870 3884)(Reuters Messaging: manolo.serapio.thomsonreuters.com@reuters.net))  Keywords: MARKETS IRONORE/