GENEVA/PARIS -- Luxury brands are again flying high in China thanks to the country's improved consumer sentiment, providing essential support to European groups' worldwide earnings.

The value of Switzerland's watch exports grew from a year earlier for the first time in 21 months in March, according to the Federation of the Swiss Watch Industry, and have only picked up speed since, thanks primarily to the mainland Chinese market. Exports to the world's second-biggest economy rose 22% year on year in the January-June half, while those to the U.S. dropped 6%.

In part, this growth reflects improving Chinese consumer confidence and a greater willingness to spend. Higher duties on luxury goods purchased overseas have also encouraged more shopping at home, rather than on trips abroad.

Swatch Group, whose luxury portfolio includes such brands as Omega and Breguet, logged group sales of 3.7 billion Swiss francs ($3.82 billion) in the first half, nearly leveling out on a year-on-year basis. Sales climbed 1% when exchange-rate swings are stripped out. This contrasts with January-June 2016, when a decline in Chinese demand pushed sales down more than 10%.

Business was even better for LVMH, the French purveyor of Louis Vuitton bags and Hennessy cognac. The world's top luxury group saw sales climb 15% in the first half to 19.71 billion euros ($23.1 billion). Net profit jumped 24% to 2.11 billion euros. Operating profit for the watch and jewelry business climbed 14%. Chinese operations are on the mend, the company said.

Kering, the French owner of luxury brands including Italy's Gucci, logged 28% revenue growth in January-June to 7.29 billion euros. Net profit surged 78% to 825 million euros. "Spending by Chinese customers on luxury goods rose sharply," and showed "especially" high growth for certain brands, according to the company. Sales also increased in Western Europe, recovering from a terrorism-related dip a year earlier.

British brand Burberry's mainland Chinese sales climbed more than 10% in the April-June quarter.