London - Copper steadied on Thursday off four-week lows touched in the previous session, underpinned by a weaker dollar as traders awaited a key US labour report and a major leadership meeting in China for clues on economic policy and metals demand.

The dollar edged down versus the euro as investors expected the European Central Bank to resist pressure to cut rates at a meeting later this session.

A weaker dollar makes dollar-priced metals cheaper for non-US investors.

On the downside however, world shares dipped before the release of the first estimate of third-quarter US GDP growth, which economists surveyed by Reuters forecast showing 2 percent annualised growth.

This data, combined with Friday's US nonfarm payrolls report, will provide the best chance for investors to gauge when the Federal Reserve might begin winding down its $85 billion-a-month bond-buying programme.

New research papers from two top Fed economists released on Wednesday called for the US central bank to drive down unemployment by promising to hold interest rates lower for longer.

“The main number will be tomorrow's US job figures. In general the mood is a little bit soft, demand is there but not in big tonnages and we have mixed news. I think prices can still come off a bit further in the next few weeks,” said Herwig Schmidt, head of sales at Triland.

Three-month copper on the London Metal Exchange edged up 0.17 percent to $7,127 a tonne by 13:31 SA time, paring losses from the previous session when it fell 0.6 percent.

Copper prices sank to $7,093 a tonne on Wednesday, the lowest since October 10 and near the bottom of the $7,000-7,420 a tonne band in place for the past three months.

Chinese leaders will start a four-day special meeting on Saturday to set a reform agenda for the next decade as they try to steer the giant economy towards more sustainable growth after three decades of breakneck expansion.

Third-quarter metals demand from top consumer China was good, and financing demand remains strong, but a wall of supply rolling in from this year will keep copper prices in check, said analyst Ivan Szpakowski of Citi in Singapore.

“We've been bearish and that hasn't changed,” he said.

“Supply growth is very good and that is likely to continue to be good all through next year. Although Chinese demand picked up in Q3, we think it will be slower going forward primarily because of tighter credit conditions,” he added.

Reflecting rising supply, miner BHP Billiton has offered treatment and refining charges (TC/RC) for shipments of copper concentrates of $80 per tonne and 8 cents a pound to Japanese smelters, reflecting a 14 percent rise from the 2013 benchmark.

In industry news, the LME revised a proposal to fix backlogs in its warehouse network on Thursday, mandating shorter queues and announcing a review of its agreement with warehouse owners.

The backlogs have tied up millions of tonnes of metal, boosting the premium to secure delivery on physical markets and incentivising otherwise loss-making producers, especially in aluminium, to continue ramping up output.

Also indicating a cautious market mood, hedge funds and money managers cut net longs or buy positions in copper for the week ended October 29, a report by the Commodity Futures Trading Commission showed on Wednesday.

In other metals, tin fell 0.99 percent to $22,599 a tonne, having earlier hit its lowest point since mid-September at $22,426 a tonne.

Weighing on tin was news that refined tin shipments from top exporter Indonesia rose to 3,314.05 tonnes in October, up four-fold from 785.99 tonnes in September.

However, exports fell 70 percent from the corresponding month a year ago.

On August 30, Indonesia introduced a regulation forcing all 47 registered tin ingot exporters to trade on a domestic exchange before shipping material, part of a plan to set its own price benchmarks for the solder material.

“Because the coming months are likely to see increased trading volume, and thus increased exports, the supply situation on the global tin market should ease again somewhat,” said Commerzbank in a note.

“Initially, this could preclude any significant rise in tin prices. At the same time, however, the average production costs of $22,000 per ton should prevent any noticeable fall in prices,” it added.

Lead fell 1.25 percent to $2,133.75 a tonne, having earlier hit its lowest since mid-October at $2,133 a tonne, while zinc fell 0.60 percent to $1,901.50 a tonne, its lowest since mid-October. - Reuters