Luxury watch marketplace WatchBox raised $165 million of equity capital in a funding round to continue its global expansion, it said on Tuesday.

The Radcliff Companies and The Spruce House Partnership were lead investors and were joined by CMIA Capital Partners along with other existing investors, WatchBox said in a statement.

WatchBox, founded in 2017, said it will use the capital to extend its digital platform and expand into new locations in the United States and internationally while enhancing its inventory.

"WatchBox's sales are up 40% year over year and we are on target to achieve $300 million in sales this year," co-founder and CEO Justin Reis told Reuters.

He said sales had gone up in all markets where WatchBox is present, from the United States to Hong Kong, Singapore, Switzerland and Dubai.

"Rolex, Patek Philippe, Audemars Piguet, and A. Lange & Sohne continue to perform incredibly well alongside leading independent brands," Reis said, adding that demand was soft in more widely distributed mid-tier brands owing to excess supply in the market.

Analysts estimate the market for second-hand luxury watches to be worth $20 billion and say it is growing faster than the primary market.

A study by Deloitte published last month showed almost one in three consumers was likely to buy a second-hand watch in the next 12 months, with younger buyers driving the trend. Deloitte said consumers bought second-hand watches because of lower prices, access to discontinued models and for investment purposes.