The Swiss group said that in the first five months of its financial year, from April to August, overall sales rose by four percent at constant exchange rates.
But the figures, once converted into euros in its accounts, showed an increase of just one percent owing to falls in the value of the dollar and yen.
The outcome was at the lower end of the range expected by analysts polled by AWP financial news agency of growth of one to four percent in euros.
The figures weighed heavily on Richemont shares which were showing a fall of 3.94 percent to 84.15 francs in mid-morning trading.
The overall Swiss SMI index was steady, edging up 0.01 percent.
Sales in the Asian Pacific region, which has been an area of rapid growth for luxury groups, stagnated on the basis of constant exchange rates, and fell by two percent in euros.
Sales fell in China, Hong Kong and Macau.
Sales in Japan dropped sharply, by eight percent in yen and by 14 percent in euros.
The downturn in Japan had been expected.
Sales there had surged at the end of the previous year ahead of an increase in Japanese sales taxes in April, which caused consumers to bring their purchases forward.
Sales in the Americas rose by 12 percent at constant exchange rates, but this represented a slowing of growth.
Purchases by tourists lifted sales in Europe and the Middle East by six percent.
Richemont, a main competitor of French group LVMH, is to report full six-month results on November 7.
At brokers J Safra Sarasin, analyst Michael Romer said that sales in Japan, and also particularly in the Asia Pacific region, "fall short of expectations".