FOREX-Dollar edges off 15-mth lows; stg falls on Fitch

* Dollar edges off 15-mth lows, but still under pressure

* Pound falls after Fitch warns on UK rating

* German ZEW eyed at 1000 GMT

(Updates prices; changes byline, dateline; previous TOKYO)

By Jessica Mortimer

LONDON, Nov 10 (Reuters) - The dollar edged up on Tuesday, reversing some of its recent losses but staying close to a 15-month low against a currency basket, while sterling fell sharply after a warning on the UK from ratings agency Fitch.

Fitch Ratings said that of the four major economies with AAA status, the UK was the most at risk, sending the pound down sharply to shed as much as 1 percent on the day against the dollar. [ID:nT286946]

David Riley, co-head of global sovereign ratings at Fitch, said if there was another significant fiscal stimulus package in Britain its rating would be at risk.

"The Fitch news was a reminder of the longer-term issues facing the UK," said Lutz Karpowitz, currency strategist at Commerzbank in Frankfurt.

Regarding other major currencies, he said the market trend was still one of dollar weakness, but that dollar short positions were looking "stretched" and the euro "lacks momentum" above the $1.50 level.

Expectations that U.S. interest rates are likely to stay near zero for a while have encouraged investors to use the dollar to fund carry trades in higher-yielding assets, particularly at times when equity markets are rallying.

The pound slipped as far as $1.6600 GBP=D4, well below a three-month high of $1.6844 reached on Monday, and fell more than 0.5 percent on the day to beyond 90.00 pence per euro EURGBP=D4.

By 0848 GMT, it was down 0.6 percent against the dollar at $1.6653, while the euro was up 0.6 percent at 89.97 pence.

An index of the dollar's performance against six major currencies edged up 0.1 percent to 75.111 .DXY, having dropped about 1 percent the previous day to as low as 74.93, its weakest since August 2008. It was the biggest one-day fall since late July.

The euro edged down 0.1 percent to $1.4986 EUR=, after gaining about 1 percent on Monday and rising above $1.50 for the first time since late October, nearing its 2009 high of $1.5064.