(BLOOMBERG) - The Michelin guide to Thailand's best restaurants will go beyond Bangkok to the southern tourism hot-spots of Phuket and Phang Nga by year's end, part of the country's efforts to keep attracting visitors.

The expanded guide will be published in November, according to the Thai unit of the French tiremaker and publisher. The review can boost tourism revenue by highlighting the different cuisines available, Tourism Authority of Thailand Governor Yuthasak Supasorn said in an interview.

"Gastronomy is Thailand's strength," Yuthasak said, adding the goal is to cover the whole country by 2021 under a five-year agreement with Michelin.

A debut Michelin guide was rolled out last year for Bangkok, long a food-lover's paradise. Indian restaurant Gaggan was among three that won two stars in the review, but none of those assessed achieved the coveted top accolade of three stars.

Yuthasak said Michelin's anonymous restaurant reviewers have been conducting inspections in the south since April.

Tourism accounts for almost 20 per cent of the Thai economy, and visitor numbers may reach 40 million next year, equivalent to more than half the population. A surge in Chinese holidaymakers has contributed to a years-long boom in arrivals, which is now pressuring nfrastructure and the environment.