* Focus on whether output curbs are extended in top producing city
* Production limits in Tangshan due to end on Friday
* China is battling to clear its notoriously polluted skies
BEIJING, Aug 27 (Reuters) - Prices for rebar construction steel in China extended losses into a fourth session on Monday, with the market waiting to see if output curbs due to end soon could be prolonged as the government continues to battle pollution.
Benchmark Shanghai rebar prices had dipped 1.3 percent to 4,240 yuan ($616.82) a tonne by 0216 GMT.
“Steel prices have certainly been supported by production restrictions amid the anti-pollution campaign. But the impact of previous measures has already been digested by the market, and investors are waiting to see if there are any further moves,” said a Shanghai-based steel trader. He declined to be identified as he was not authorised to speak with media.
A rally in Chinese steel prices over the last two weeks has partly been driven by expectations that production restrictions due to expire on Friday in the top steelmaking city of Tangshan in Hebei province could be extended.
The local government has not made any official comment on the issue.
“Utilisation rates at steel mills across the country could climb to around 70 percent if operations resume in Tangshan,” analysts from Huatai Futures wrote in a note.
Weekly utilisation rates were at 66.44 percent last week, according to data from Mysteel consultancy.
“But it is still uncertain if Tangshan will ease the restrictions, since air quality in the city has not seen clear improvement.”
Steelmaking raw materials mostly fell alongside rebar prices on Monday, with many traders staying on the sidelines until the outlook for steel production becomes clearer.
The most-active iron ore futures on the Dalian Commodity Exchange dipped as much as 2.7 percent to 476.5 yuan a tonne, their lowest in a month.
Dalian Coking coal prices dropped nearly 0.1 percent to 1,280 yuan a tonne.
Coke futures for January delivery edged up 0.1 percent to 2,516 yuan a tonne, buoyed by environmental inspections in major coke producing hubs in Shanxi and Shaanxi provinces.
$1 = 6.8740 Chinese yuan renminbi Reporting by Muyu Xu and Josephine Mason Editing by Joseph Radford