Yen tumbles in London

The yen fell more than half a percent against the dollar, euro and sterling on Friday, pressured by weaker than expected Japanese growth data which triggered further position adjustment.
The euro softened against the dollar ahead of US July retail sales data at 1230 GMT, which will be scanned for any signs of slowing in the world's biggest economy.
Japanese gross domestic product expanded at a 0.8 percent annualised pace in the April-June quarter, softer than market forecasts for a 1.8 percent rise and reinforcing expectations the Bank of Japan will lift interest rates only gradually.
"The GDP was somewhat weaker than expected and that has caused yen weakness," said Teis Knuthsen, head of FX and fixed income research at Danske Markets in Copenhagen.
"We have been seeing moves which are technically-driven, and the dollar has been bouncing back and forth," he added. The dollar hit a two-week high against the yen of 116.12 yen and was trading at 116.03 yen at 1118 GMT, up 0.70 percent on the day. Analysts said the yen has risen against the dollar every August in the past eight years, so investors may have been caught short of dollars and were covering positions.
"A lot of people were expecting the yen to strengthen in August," said Stuart Ritson, currency strategist at Rabobank. The euro rallied 0.53 percent to 148.22 yen, close to a record peak of 148.60 yen set on Thursday, according to Reuters data.
Sterling rose as far as 220.04 yen, close to recent 8-year highs and up nearly one percent on the day. Sterling was up two yen from lows set on Thursday after Britain said police foiled a plot to blow up transatlantic flights.
The euro fell a quarter percent to $1.2783, off a two-month high of $1.2913 struck the previous session.
Economists in a Reuters survey expect a median 0.8 percent rise in July US retail sales compared with a 0.1 percent fall in June. Excluding automobiles, sales are seen up 0.5 percent after a 0.3 percent rise the previous month.
The euro got little cheer from surprisingly strong French growth data. French GDP rose by 1.1-1.2 percent in the second quarter compared with the first three months of the year, its fastest pace of growth in almost six years.
French Finance Minister Thierry Breton told Le Monde newspaper that the euro was fully valued, and it was in no one's interest for the United States to pursue any policies that would result in a sharp weakening in the dollar.
The Bank of Japan held rates steady at 0.25 percent as widely expected and Governor Toshihiko Fukui said he was neither ruling out nor implying there would be another rise in borrowing costs by the end of the year.
Despite the unexpectedly sharp slowdown in Japanese growth, analysts said firming consumer spending and solid business investment would underpin growth and likely spur a rebound in the current quarter.
"The breakdown of the second quarter was actually quite good - it still shows that domestic demand conditions in Japan are very strong," BOTM-UFJ currency economist Derek Halpenny said.
Sterling held its ground against the dollar and the euro, having fallen the previous day after the police bomb statement. The pound was little changed from the US close at $1.8937 and was up slightly against the euro at 67.42 pence.