By Atul Prakash

LONDON (Reuters) – The FTSE 100 hit a six-week high on Thursday, with miners leading the market higher tracking firmer metals prices, while Anglo American also reported strong output numbers.

The UK mining index, the biggest sectoral gainer, was up 1.4 percent. Anglo American rose 3.2 percent to the top of the blue-chip FTSE 100 index after its copper output rose 18 percent and iron ore 10 percent in the first quarter.

“AAL’s update shows a stronger output and an increase in guidance for copper. With recent Chinese PMI data still showing a reading below 50, this update and the upcoming updates from the world’s largest miners may go some way to ease investors’ nerves,” Tom Robertson, senior trader at Accendo Markets, said.

Other miners also gained, with Antofagasta up 1.1 percent and Rio Tinto rising 1.4 percent, helped by a rise in key industrial metals prices, underpinned by strong seasonal demand in top consumer China and supply concerns.

Basic resources shares helped the FTSE 100 to trade 0.5 percent higher at 6,709.60 points by 9.11 British Time after it hit a six-week high of 6,713.73 points.

However, charts suggested that investors remained cautious despite the index bouncing back after falling last week to touch a major support line in the form of its long-term uptrend at around 6,500.

“The good news for the bulls is that this line still appears to be providing solid support, as does the 200-day moving average,” Bill McNamara, analyst at Charles Stanley, said.

“The fact that the index bounced so modestly following three weeks of declines …looks like a clear indication that investors remain cautious. The FTSE might not be finished with its test of support,” he said adding the index could fall as low as 6,492 points in the near term.

Among individual movers, AstraZeneca rose 2 percent after highlighting progress with a new generation of cancer drugs that may revive its fortunes as it posted a 17 percent fall in core earnings per share.

ARM Holdings rose 0.7 percent after U.S. tech giants Apple and Facebook posted strong results late on Wednesday, boosting their shares in after-hours trading.

(Reporting by Atul Prakash; Editing by John Stonestreet)