Swatch group executives said business has bounced back quickly when markets reopen.
The monthly statistics show signs of a recovery, noted Bernstein analysts.
The expansion project comes as Swiss watch exports continue to decline.
China was a bright patch, with a 16.1 percent decline over the month.
A 43.2 percent decline in volumes represents the market situation better, said Federation of the Swiss Watch Industry.
Volumes dipped below the level seen in the crisis year 2009.
Exports to mainland China rose 17.6 percent, offering evidence that luxury purchases are shifting to other markets.
Sales to Hong Kong, the industry’s largest market, have slowed since late last year.
Pricey watches helped offset the ongoing decline of cheaper timepieces.
The company will present a new product featuring an automatic movement from Kenissi at Baselworld in March this year.