* Steel rebar slips after brief recovery
* Trading volatile ahead of year-end
BEIJING, Dec 29 (Reuters) - Chinese steel rebar prices fell more than 2 percent, reversing the previous day's gains, while coke and coking coal remained under pressure on Thursday as concerns about weakening demand returned in volatile end-of-year trading.
"The pullback shows traders are not confident about the steel market and future demand during the winter," said Wang Yilin, steel analyst at Sinosteel Futures.
The most-active rebar contract for May delivery on the Shanghai Futures Exchange was down 2.3 percent at 2,948 yuan ($423.89) per tonne at 0323 GMT.
Prices have been seesawing on a daily basis this week amid low turnover with major international exchanges shut for the Christmas holidays and ahead of the New Year.
Iron ore on the Dalian Commodity Exchange eased 0.4 percent to 561.5 yuan a tonne.
Steel mills typically curb their output as the construction industry slows during the quieter winter months and ahead of the Chinese Lunar New Year holiday at the end of January.
Factory closures due to widespread pollution across northern China last week renewed concerns that consumption of raw materials like iron ore and coking coal may fall harder than is usual for this time of year.
The most-active coking coal futures on the Dalian Commodity Exchange were down 3.1 percent at 1,146.5 yuan per tonne, after falling to the lowest since Oct. 18 on Tuesday.
Coke fell 3 percent to 1,519.5 yuan per tonne. On Tuesday, prices hit their weakest since Nov. 3. ($1 = 6.9546 Chinese yuan renminbi) (Reporting by Josephine Mason; Editing by Christian Schmollinger)