* Dalian iron ore off one-month high
* Little physical trading seen ahead of China holiday
* China Jan official manufacturing PMI lowest since 2012 (Updates prices)
By Manolo Serapio Jr
MANILA, Feb 1 (Reuters) - Iron ore and steel futures in China trimmed gains on Monday as trading activity in the top consumer of both commodities slows ahead of next week's Lunar New Year holiday.
Chinese markets will be shut Feb. 8-12 and a Shanghai-based iron ore trader said a few small steel producers are planning to put their plants on maintenance during that period.
The price of construction-used rebar for May delivery on the Shanghai Futures Exchange SRBcv1 closed up 0.2 percent at 1,819 yuan ($277) a tonne, off a session-high of 1,845 yuan.
On the Dalian Commodity Exchange, May iron ore DCIOcv1 rose to a one-month peak of 330 yuan a tonne, but surrendered some gains to close at 324.50 yuan, up 1.4 percent.
March iron ore on the Singapore Exchange SZZFH6 slipped 0.4 percent to $40.90 a tonne.
The period following the Lunar New Year has typically been a strong consumption season for steel, but many traders were not optimistic for this year due to a slowing economy.
China's manufacturing activity contracted at its fastest pace in almost three-and-a-half years in January, an official survey showed, suggesting the world's No. 2 economy is off to a weak start in 2016. was little activity in physical markets ahead of next week's holiday, traders said. The brief closure of iron ore ports in Australia over the weekend due to a tropical cyclone did not lead to major shipment disruptions, they said. {nL3N15F03I]
"I don't expect prices to move much. Some staff are already taking leave," said the trader.
Iron ore for immediate delivery to China's Tianjin port .IO62-CNI=SI was flat at $41.50 a tonne on Friday, according to The Steel Index.
But the spot benchmark still ended January down more than 3 percent, marking its fourth monthly loss in five, amid a glut-hit market.
Rebar and iron ore prices at 0701 GMT
Contract
Last
Change Pct Change SHFE REBAR MAY6
1819
+4.00
+0.22 DALIAN IRON ORE DCE DCIO MAY6
324.5
+4.50
+1.41 SGX IRON ORE FUTURES FEB
41.8
-0.20
-0.48 THE STEEL INDEX 62 PCT INDEX
41.5
+0.00
+0.00 METAL BULLETIN INDEX
41.72
-0.20
-0.48
Dalian iron ore and Shanghai rebar in yuan/tonne Index in dollars/tonne, show close for the previous trading day ($1 = 6.5772 Chinese yuan)