PARIS/MILAN, Nov 20 (Reuters) - The global luxury goods industry is likely to sell 3% to 5% more next year after stagnating in 2025, but years of aggressive price increases have alienated customers, threatening long-term growth, Bain & Company warned on Thursday.

Bain said next year's growth will be driven by continued momentum in the United States, resilient local demand in Europe and Japan, and progressively improving trends in China.

The consultancy, however, said persistent price hikes have pushed high-end fashion brands out of reach for aspirational buyers while leaving even ultra-wealthy clients feeling "betrayed" - a strong reversal of the "elevation" strategy that dominated the industry in recent years.

"You cannot target only the top customers. Because they are also starting to really be upset and to feel betrayed in this industry," said Bain partner Federica Levato, citing price hikes at odds with a perceived lack of creativity.

"Some of the brands may have realized that they made mistakes, but most of them think that they can fix the mistakes with new creativity. So increasing the level of creativity at the same price that they have today, in our belief, won't be enough."

The luxury customer base has shrunk to around 340 million people in 2025 from 400 million people in 2022 and looks set to lose 20 to 30 million more clients, according to the study produced with Italian luxury industry group Altagamma.

Even big spenders show signs of fatigue. While they now account for roughly 46-47% of the €358 billion personal luxury goods market, their spending has plateaued this year, the study found.

The price push by most traditional luxury brands has created "a complete void in the market" for companies offering more affordable clothing, said Levato, many of which are American.

In an early sign of what could become a wider industry reckoning, Kering CEO Luca de Meo said in a memo seen by Reuters this week that the group needed to rethink its pricing and product range after years of increases.

The strategy also priced out younger shoppers, who despite limited budgets have outsized cultural influence and shape the spending decisions of older generations. "This industry really walked away from Gen Z," Levato said.

The industry slowdown has resulted in mounting inventory, with stock-to-revenue ratios up 3-4 percentage points versus 2019, Levato said, recommending using outlet and off-price e-commerce to clear excess product.

Handling excess inventory has become a headache in an industry where many brands are wary of discount channels to protect their image and destroying unsold products is banned under EU sustainability rules.

Forecasting the trajectory of the global luxury industry has become particularly challenging due to geopolitical uncertainty, including the trade policies of U.S. President Donald Trump and continued question marks over the fate of the Chinese economy.

Bain heavily slashed its initial 2025 outlook last May to a 2 to 5% fall in 2025, but on Thursday said the industry was set to end the year largely flat.

Luxury shares have rallied in recent months, with the Stoxx Luxury 10 index up 19% from its April lows, buoyed by encouraging third-quarter earnings from LVMH, Burberry and Richemont signaling improved shopper sentiment, particularly in China.

(Reporting by Elisa Anzolin and Tassilo Hummel; editing by Philippa Fletcher)

((tassilo.hummel@thomsonreuters.com))