Global miner BHP Billiton sold several cargoes this week at prices around $3 more than previous deals, traders said, adding the bulk of the buyers could be traders positioning ahead of an expected rebound in China's steel prices. Australian Pilbara iron ore fines with 61.5 percent iron content was quoted at $138-$140 a tonne, cost and freight, up $2 from Thursday, according to Chinese consultancy Umetal. Offers for other cargoes rose $1 a tonne, with Australian 63-grade Newman fines at $140 to $142 and Yandi fines at $126 to$129. Indian 63.5/63-grade iron ore fines were also quoted a dollar higher at $145 to $147 per tonne. BHP Billiton sold via tender two or three capesize cargoes of high-grade Newman iron ore fines on Thursday at $141.35 to$141.75 a tonne and MAC fines at $137.25 to $138.75 per tonne, said a physical dealer in Shanghai. "Some traders are trying to push up the price because they think steel demand would pick up in March when the weather turns better and construction activity resumes in China," he said. BHP rivals Rio Tinto and Vale were also offering more cargoes on Friday. Iron ore with 62 percent iron content rose 2.1 percent to $138.70 a tonne on Thursday, said reference price provider the Steel Index, its biggest percentage gain since Dec. 21. It marked a fourth straight day of gains for iron ore.