* FTSE 100 down 0.9 pct, around 1-month low
* Chinese credit concerns hit mining stocks
* Ex-dividends take around 20 points off index
By Tricia Wright
LONDON, March 12 (Reuters) - Britain's top equity index fell on Wednesday to hover around a one-month low as heightened concerns over the credit market in China, the world's top metals consumer, hit the mining sector for the fourth straight session.
The FTSE 350 Mining Index fell for the fourth day in a row to trade 0.7 percent lower. The recent sell-off has tipped the sector into negative territory for the year, down 1.7 percent.
Miners were hit as Shanghai futures fell by their 5 percent daily limit again and London Metal Exchange prices dropped to their lowest since 2010.
The blue-chip FTSE 100 index, which had already fallen in the last three sessions, was down by 57.43 points, or 0.9 percent, at 6,628.09 points by 1138 GMT.
A bond default last week by a Chinese solar company reignited concerns about a possible economic slowdown in China, which in turn has hit metal prices and mining stocks.
China's health is a key factor for the FTSE 100, given the mining sector's heavy weighting. It is the fourth biggest sector within the UK benchmark, accounting for almost 9 percent of the index, data from index compiler FTSE showed.
Although the UK stock market has been propped up by a gradual recovery in the British economy, some traders expected the FTSE to remain under pressure in the near-term, with the index down 1.8 percent since the start of 2014.
"The UK market remains vulnerable with especially the mining sector under huge pressure... Unlikely that we have seen the last of this and my preference would be to sell rallies," Lex van Dam, hedge fund manager at Hampstead Capital, said.
Barclays Capital analyst Lynnden Branigan saw scope for the UK benchmark, which has this week fallen below both its 50-day and 100-day moving averages, to drop down to its 200-day moving average, at 6,578, "within the next five days, for sure".
"There is a risk of a squeeze below, towards perhaps 6,500," he said.
The FTSE 100 rose 14.4 percent in 2013 to record its best annual gain since 2009. It also reached peaks that marked its highest level in around 13 years in early January this year.
A host of companies, including major banks HSBC and Standard Chartered went ex-dividend on Wednesday.
Investors who buy a stock on or after its ex-dividend date are not entitled to the dividend payment, and the companies going ex-dividend had the technical impact of taking some 20 points off the FTSE 100 index.