At 1.8-billion francs, the monthly total remains high but the overall number of timepieces exported continued a steady decline, the FH said.
The federation said last month’s drop was largely attributable to to fewer gold watches being sold.
“Only watches between 200 and 500 francs (export price) showed a positive result in May,” FH said.
The number of Swiss wrist watches exported in the first five months of the year fell by 7.3 percent to 10.73 million compared to the same period in 2012, the federation said.
But the overall value of watch exports for the period remained positive, up 1.7 percent to 8.73 billion francs, although growth is slowing.
Exports to Hong Kong, the biggest market, fell 15.7 percent in May, while those to China, the fourth biggest market, fell by 19.4 percent.
Switzerland and China signed an accord last month that would drop Chinese tariffs on Swiss watches.
Exports to the United States, the second biggest market, remained flat, while sales to Italy (third biggest market) and Germany (fifth biggest market) continued to grow but at a slower rate, FH said.