* Retail sales surprise with 0.5 pct month-on-month fall
* Decline comes despite improving labour market figures
* Online, mail order spending down 10.3 pct year-on-year
(Recasts, adds details, economist quote)
By Brian Rohan
BERLIN, Oct 30 (Reuters) - German retail sales fell unexpectedly in September, data showed on Friday, in a sign consumers in Europe's largest economy are reining in spending despite government efforts to prop up the labour market.
Retail sales fell 0.5 percent month-on-month in real terms and fell 3.9 percent on an annual basis, their fifth straight decline, figures from the Federal Statistics Office showed.
Economists had forecast a 0.6 percent rise on the month and
a more modest 2.5 percent year-on-year dip
A breakdown of the annual data showed households were holding back on a broad range of purchases, with online and mail order items down 10.3 percent in real terms and clothing and food also declining.
"The economic boost from private consumption is running out. Consumption will no longer contribute positively to growth. The conditions for retail are difficult," said economist Lothar Hessler from HSBC Trinkaus.
The figures come days after Chancellor Angela Merkel's new centre-right coalition of conservatives and Free Democrats (FDP) was sworn into office, promising billions of euros in tax relief to shore up growth.
Germany is emerging from its deepest recession since World War Two, but government stimulus measures have played an important role -- prompting concerns over whether the recovery is sustainable.
Unemployment, which fell in October for a fourth month running, has been kept in check by a "Kurzarbeit" subsidy scheme which encourages firms to shift employees to part-time work rather than fire them.
But layoffs are expected to accelerate next year and smaller paychecks already appear to be hitting the purchasing power of German consumers.
"The good times for retail are over for now. The labour market is holding up surprisingly well (but) sooner or later, unemployment is going to rise substantially," said Ulrike Kastens from Sal. Oppenheim.
TAX CUT PROMISES
Showing the pressure on the sector, German mail-order
company Quelle -- a unit of now-insolvent Arcandor
Household spending makes up around 60 percent of German economy. The HDE retailers' association has welcomed the new government's promised tax cuts as a way to boost spending, although it said last month it expects sales to fall by around two percent in nominal terms in 2009.
Some experts say the retail sector has suffered because a popular government car-scrapping scheme diverted purchases towards cars and away from other areas.
In nominal terms, retail sales fell 0.5 percent month-on-month and decreased 4.8 percent on the year, the Office said. In the first nine months of 2009, sales were down by 2.2 percent in real terms year-on-year.
The figures were based on sales data from seven states accounting for around 76 percent of retail activity in Germany. (Additional reporting by Noah Barkin, editing by Mike Peacock and Patrick Graham)