Europe's main stock markets were in the red at the start of trading on Wednesday, held back by a decline in the luxury goods sector following Kering's earnings warning, and by caution ahead of the conclusion of the U.S. Federal Reserve's (Fed) monetary policy meeting.

In Paris, the CAC 40 lost 0.84% to 8,132.40 points around 08:40 GMT. In London, the FTSE 100 gave up 0.17% and in Frankfurt, the Dax was down 0.12%.

The EuroStoxx 50 index was down by 0.45%, the FTSEurofirst 300 by 0.34% and the Stoxx 600 by 0.29%.

Wall Street futures point to a decline of 0.05% for the Dow Jones, 0.08% for the Standard & Poor's-500 and 0.05% for the Nasdaq.

Among stocks, the morning was marked by the collapse of Kering shares, down 14.7%, after the luxury goods group warned on Tuesday that first-quarter sales of its flagship Gucci brand would fall by around 20% due to weak demand in Asia. In Kering's wake, the European luxury goods sector lost 2.3%.

Valneva lost 3.2% after its annual results, while Eutelsat gained 3.3% following the announcement of a partnership with Intelsat.

Bureau Veritas gained 3.8% after announcing several acquisitions in Asia and financial forecasts to 2028.

Elsewhere in Europe, Swiss pharmaceuticals manufacturer Lonza

gained 3.7% after signing an agreement to acquire Genentech's production site in Vacaville, California, from drugmaker Roche for $1.2 billion (€1.1 billion) in cash. (Written by Augustin Turpin, edited by Blandine Hénault)