(IDEX Online) - Richemont saw overall sales rise sharply, by 24 per cent in the six months to the end of September.But the Swiss luxury goods conglomerate, which owns Cartier, Van Cleef & Arpels and Jaeger-leColutre, warned of "volatile times ahead".It reported revenue during the period at $9.9bn, and said operating profit was up 26 per cent to $2.8bn.The results were better than expected, especially in Europe with tourists from North America and Middle East taking advantage of a recent slide in the value of the euro.Richemont said its jewelry maisons had reaffirmed their leading position and its specialist watchmakers had increased sales by 22 per cent.It noted a "continued shift in demand towards directly operated stores, both physical and online, and mono-brand franchise stores".However, chairman Johann Rupert said: "It is highly uncertain how the political, economic and social landscapes will evolve in Europe and in our other key markets. "We only know that we will likely face volatile times ahead as central banks seek to rein in inflation while governments try to manage severe cost of living pressures."