COPENHAGEN, Sept 14 (Reuters) - Danish jewellery maker Pandora (PNDORA.CO) plans to produce edgy pieces to attract young shoppers and significantly boost sales in the United States and China to meet a revenue growth target of 6-8% over 2021-2023 it announced on Tuesday. The world"s largest jewellery maker by production capacity said it was also targeting an operating profit margin of 25-27% in 2023 and boosted its ongoing share buyback, driving its shares up more than 4%. Pandora has looked to refresh its image to appeal to the so-called "Gen Z" - people aged six to 25 whom Bank of America says represents some 2.5 billion people who make up 32% of the global population, followed by "Millenials" aged 25 to 40 at 22%. "If you look at Generation Z and Millenials, by 2025 they are expected to constitute over 60% of the luxury consumption in the world so we need to sharpen our pens," CEO Alexander Lacik told Reuters. Summary Pandora sets new mid-term targets Hikes ongoing share buyback scheme Shares rise more than 4% Aims to attract younger consumers Aims to double U.S. revenue, triple sales in China COPENHAGEN, Sept 14 (Reuters) - Danish jewellery maker Pandora (PNDORA.CO) plans to produce edgy pieces to attract young shoppers and significantly boost sales in the United States and China to meet a revenue growth target of 6-8% over 2021-2023 it announced on Tuesday. The world"s largest jewellery maker by production capacity said it was also targeting an operating profit margin of 25-27% in 2023 and boosted its ongoing share buyback, driving its shares up more than 4%. Pandora has looked to refresh its image to appeal to the so-called "Gen Z" - people aged six to 25 whom Bank of America says represents some 2.5 billion people who make up 32% of the global population, followed by "Millenials" aged 25 to 40 at 22%. "If you look at Generation Z and Millenials, by 2025 they are expected to constitute over 60% of the luxury consumption in the world so we need to sharpen our pens," CEO Alexander Lacik told Reuters. The company generates 70% of its sales from its Moment platform based on silver bracelets with collectable charms but is hoping to build a new growth pillar with pieces catering to younger people. It will soon launch more pieces in its Pandora Me collection, which has previously been promoted by English actor and model Millie Bobby Brown, and is both cheaper an has a more raw look than conventional pieces with for example safety brooches or chains. Lacik took over the helm in 2019 after the previous CEO was ousted following several profit warnings and a lack of new innovative products. A top priority for Lacik is to gain a foothold in China, the world"s largest jewellery market, where its brand penetration is still very low. Pandora said it aims to triple revenue in China compared to 2019 levels and double sales in the United States. To meet demand, it will invest 1 billion Danish crowns ($159 million) in expanding its manufacturing capacity by around 60%, or 80 million pieces of jewellery annually, by building a new factory in Vietnam and expanding its existing plants in Thailand ($1 = 6.2947 Danish crowns)