* Euro hits 6-week low vs dollar, pound close to 23-yr lows
* Euro zone flash PMIs, UK Q4 GDP and retail sales data eyed
* European shares fall 0.6 percent, supporting the yen
(Updates prices, changes byline, dateline; previous TOKYO)
By Jessica Mortimer
LONDON, Jan 23 (Reuters) - The euro hit a six-week low against the dollar on Friday, while the pound hovered close to its two-decade trough versus the U.S. currency as investors awaited key European and UK data.
The yen continued to gain, benefitting from its perceived safe-haven status as global economic worries pushed European shares down 0.6 percent.
Downward pressure on the euro is expected to continue as provisional purchasing managers' surveys on euro zone manufacturing and services sector activity due around 0900 GMT are forecast to give more evidence of a deteriorating economy.
Market attention will also focus on UK data at 0930 GMT that is widely forecast to show the economy fell into recession in the fourth quarter, while retail sales slid in December.
Sterling has come under severe pressure recently as worries about a very weak economy combined with concerns about the UK's troubled banking sector and the parlous state of government finances.
"It is very much a case of continued worry about the global economy," BNP Paribas currency strategist Ian Stannard said.
This is keeping the yen and the dollar supported, while data revealing "the extent of the slowdown" in both the euro zone and the UK will keep the euro and the pound in the red, he said.
The euro fell over one percent against the dollar to a six-week low of $1.2810, while the pound slid 1.3 percent to $1.3670, near Wednesday's quarter-of-a-century trough around $1.3618.
This pushed the dollar index to a six-week high of 86.525.
The yen continued to gain broadly, with the dollar down 0.6 percent at 88.25 yen and the euro falling 1.9 percent to 113.21 yen.
The dollar was supported by comments from U.S. Treasury Secretary nominee Timothy Geithner, who said a strong dollar is in the United States' interest.
His remarks came on Thursday when he won the Senate Finance Committee's backing to head the U.S. Treasury.
Traders said the yen remained well-bid as a relatively safe currency because investors' risk aversion remained elevated on worries about the deepening global recession.
This weighed on riskier and higher-yielding currencies, with the Australian dollar touching a six-week low against the U.S. dollar of $1.6440.
Market players were on the lookout for any comments from Japanese authorities about possible currency intervention to stem the yen's rise.
Japanese Finance Minister Shoichi Nakagawa said on Friday that he was watching financial markets very carefully.
Economic problems in the United States and Europe were affecting Japan's stock and currency markets, Nakagawa told a news conference.
"If the dollar drops below 85 yen, or the currency market moves sharply, caution about Japanese intervention will increase," said Kazuyuki Kato, treasury department manager at Mizuho Trust & Banking.
"But it is unlikely that Japan will intervene at current market levels," he added.
Worries are also growing about the possibility that the Swiss National Bank could intervene to weaken the Swiss currency, which, like the yen, has gained as investors seek safer assets. (Reporting by Jessica Mortimer; Editing by Andy Bruce)