Copper was steady on Thursday, after a 2 percent fall the previous session, and was on track for a 10 percent increase this quarter, although doubts over demand in China and over the pace of economic recovery in the U.S. made investors cautious.

Benchmark copper on the London Metal Exchange (LME) was trading at $8,336 a metric ton, little changed from a close of $8,349 on Wednesday.

The metal, used in power and construction, started the week on a strong note after the Federal Reserve suggested further monetary easing could not be ruled out.

It pared gains later in the week as weaker-than-expected economic data from the U.S. cast doubt on the pace of recovery in the world's largest economy and raised concerns about base metals demand growth rate.

The red metal is now on track for a 10 percent increase this quarter after having risen as much as 15 percent in February. Tin, the best performing metal so far, was on course for a 17 percent quarterly increase, zinc for a 8 percent rise while aluminum was up 6 percent on the quarter.

Copper this quarter is in the middle of the pack. All these base metals will show reasonable growth this year; not as good as last year, but reasonable, and the second quarter is seasonally stronger for manufacturing around the world, said Nick Moore, an analyst at RBS.

For all base metals there is a supply surge underway but copper risks another handsome supply shortage and we know China is structurally short. They need to import millions of metric ton.

The biggest losers so far were lead, down 3 percent on the quarter, and nickel, down 6 percent.

These are some of the most heavily supplied markets.

LME inventories of nickel have risen sharply to eight-week's worth of consumption and we expect a 50,000 metric tons surplus in 2012, Moore said. It's a fully supplied market and new projects are coming on stream.

ZINC OUTLOOK GLOOMY

Prices of zinc surpassed lead this month for the first time since September 2011, reversing the traditional relationship, despite ballooning LME zinc inventories.

Zinc stocks in warehouses monitored by the London Metal Exchange (LME) jumped to the highest in nearly 17 years on Wednesday, climbing steadily after years of market surpluses.

The fundamental outlook is becoming increasingly gloomy on the zinc market, said Commerzbank in a research note.

There is no likelihood of these high stocks being significantly reduced in the foreseeable future, for the global zinc market, which has been in surplus since 2007... Because zinc is used mainly in the galvanization of steel, zinc demand could decline as growth in the steel industry becomes less dynamic.

Zinc was at $1,993 from $2,000 at Wednesday's close while battery material lead was at $1,963 from a last bid of $1,986.

Tin was unchanged at $22,425 and aluminum was at $2,145.75 from $2,196.

Nickel was at $17,456 from $17,575.