The most active rebar contract on the Shanghai Futures Exchange, October, ended at 4,794 yuan a tonne, holding near an eight-session high, having hit a four-month low of 4,627 yuan on March 22.

Late Wednesday, Baoshan Iron & Steel , China's top listed steelmaker, posted an 8.3 percent rise in quarterly profit, and said it expected growth in global steel demand to slow this year.

"The important thing to note is that it's growing, not slowing. Maybe it's not growing as quickly as before but the rates we saw in 2009 and 2010 were unsustainable, built on all that stimulus money," said a trading source in Sydney.

"It looks like demand growth will moderate. We still have a bit of an inventory hump to get over, which in the short term may cap steel prices, in particular in China and even cause a lull in iron ore demand in the next three to six months, but it's temporary."

Key iron ore indexes, based on spot transactions in China, rose sharply on Wednesday.

India's iron ore exports fell for the eighth straight month in February because of a continuing ban on shipments by its key Karnataka state and exports are likely to face further pressure as the country hikes freight rates again.

Exports from the world's No. 3 iron ore supplier dropped 18.6 percent from a year ago to 10.137 million tonnes in February, data from the Federation of Indian Mineral Industries showed on Wednesday.

In addition, Indian Railways said it will impose a "busy season" charge of 7 percent on iron ore freight rates from April 1 to June 30 and from Oct. 1 to March 31.

Platts 62 percent iron ore index jumped $5.50 to $175 a tonne, including freight, and the Steel Index's 62 percent benchmark gained $2 to $170.50.

Metal Bulletin's 62 percent gauge rose $1.74 to $169.71.