Red Bull co-owner Chalerm Yoovidhya heads Thailand's richest family according to the latest Forbes list, but the combined wealth of Thailand's 50 richest fell by 15%.

Forbes Asia said on Wednesday that Mr Chalerm's family increased their wealth by US$2.6 billion (95.8 billion baht) to $36 billion (1.3 trillion baht). It said Red Bull's revenue exceeded $11 billion (405.5 billion baht) last year with global sales of more than 12 billion bottles and cans.

The Chearavanont brothers, of Charoen Pokphand Group fame, dropped to second after topping the Thailand's 50 Richest list for nearly a decade. Their wealth dropped from $34 billion (1.2 trillion baht) last year to $29 billion (1.1 trillion baht) this year. Forbes Asia attributed the drop partly on the falling fortunes of one of their holdings, Ping An Insurance in China.

Charoen Sirivadhanabhakdi of Thai Beverage remains in third position, with estimated wealth of $10 billion (368.6 billion baht), down $3.6 billion (132.7 billion baht) from last year.

The Chirathivat family retains fourth spot with $9.9 billion (364.9 billion baht), down 20% from $12.4 billion (457.1 billion baht) last year. The family's Central Group raised its shareholding in Selfridges department store in London in November and became the major shareholder.