* Rebar futures have gained over 26 pct this year
* Spot iron ore prices have dropped 8 pct (Adds Hebei plan to cut truck pollution, updates prices)
By Manolo Serapio Jr
MANILA, Aug 22 (Reuters) - Shanghai rebar steel futures pulled back after scaling a seven-year high on Wednesday as investors locked in gains, but prices are expected to be supported by China's production restrictions that have kept supplies tight in the world's top producer.
The price of the construction steel product has surged more than 26 percent this year and could strengthen further with construction activity expected to pick up ahead of further output curbs in winter.
The most actively traded January rebar on the Shanghai Futures Exchange SRBcv1 rose more than 1 percent to 4,418 yuan ($643) a tonne, its highest since September 2011, before retreating to close 0.8 percent lower at 4,334 yuan.
"In view of this consistency in China's policy in reducing pollution, I'm confident that steel prices will be supported by these production cuts in the longer term," said Argonaut Securities analyst Helen Lau.
"There's also a lot of construction activity in autumn that will drive demand."
Apart from ongoing production curbs implemented by Chinese cities including top steel producer Tangshan, northern mills will be required to cut capacity by 30 percent-50 percent over winter, the second straight year such measures will be enforced. will enforce emergency pollution-reduction measures from Tuesday till Aug. 27, as the city government said it expects to see adverse weather conditions that would worsen the pollution levels in the region. Hebei province, where Tangshan is located, officials said they aim to slash road freight in favour of rail and river transport over the next two-and-a-half years as part of efforts to improve air quality. steelmaking raw materials, coking coal futures on the Dalian Commodity Exchange DJMcv1 climbed as much as 4.1 percent to 1,362.50 yuan a tonne, the highest since March 1. It closed up 1.9 percent at 1,333 yuan.
The rally in coking coal came after the surge in coke prices last week.
Coke is the processed form of coking coal and curbs in coke production, which is also covered by China's anti-pollution campaign, had sent prices to a record high on Friday, breeding hoarders amid fears of further output restrictions as inventories dropped to two-year lows. DCJcv1 climbed 0.2 percent to 2,610 yuan a tonne. Iron ore DCIOcv1 slid 2.4 percent to 485 yuan.
Spot iron ore for delivery to China's Qingdao port .IO62-CNO=MB fell 1.9 percent to $66.54 a tonne on Tuesday, according to Metal Bulletin. It was the lowest level since Aug. 26 for the spot benchmark, which has lost 8.4 percent this year.
($1 = 6.8740 Chinese yuan)