PARIS, Sept 27 (Reuters) - A global surge in pea prices linked to low supplies and growing demand for plant protein will inevitably need to be passed on to customers, including makers of alternative food such as meat-free burgers, French producer Roquette said on Monday.

The market for alternative protein has soared in recent years, attracting major investment from global agrifood groups, including Nestle, PepsiCo and Archer Daniels Midland, hoping to capitalise on a trend towards healthier eating.

But pea production slumped this year due mainly to a severe drought this summer in top supplier Canada that cut ouput by 45%, pushing prices up 120% from last year, Roquette said in a statement.

Meanwhile in France the crop was severely damaged by wet weather during harvest.

"The dramatic increase in prices will inevitably lead to costs being transferred to customers," Roquette said.

The company declined to give details on price rises it is considering passing on to its customers globally.

Family-run Roquette is the largest pea protein producer for the food market. It built the world's biggest pea protein factory in Manitoba, Canada, which is due reach full capacity in 2022, processing some 125,000 tonnes of peas a year. It also has a pea protein factory in northern France.

Last year it signed a three-year supply agreement with U.S. plant-based burger maker Beyond Meat to end-2022.

The global pea protein market is projected to increase about 12% per year to reach $554.9 million by 2028, according to research firm Grand View Research.

(For a graphic on rising global protein consumption and demand for peas, see: https://tmsnrt.rs/2Hc8Wjw)

Other key ingredients of plant-based protein such as soybeans, corn and wheat have also seen prices rally over the past year on strong international demand and a lack of global supplies. (Reporting by Sybille de La Hamaide; Editing by Kirsten Donovan)