A total of 154 companies feature on the list compiled by Burma Campaign
More companies now have business links with Burma's ruling military junta, according to pressure group Burma Campaign UK.
Fifty new companies have been added to the group's "dirty list" of companies, including Toyota, Kuoni, BBC Worldwide and Qantas.
The group claims the firms directly or indirectly finance the Burmese regime.
Three of the companies listed said their commercial activities did not support the regime.
Many of the companies on the list are involved in the oil and gas sector or with tourism.
"By being there, these companies are financing a regime that is one of the most brutal regimes in history," said Johnny Chatterton, campaigns officer at Burma Campaign UK.
"The foreign exchange these firms generate allowed the regime to double the size of its army," he added.
The jump in the number of firms appearing on the list is the result of investment in Burma's gas sector and new information, the group said.
Car maker Toyota said it had sold fewer than 40 vehicles in Burma, predominantly to embassies or the United Nations.
"We do not sell vehicles to government agencies nor officials," a spokesperson for the company said.
However, Toyota Tsusho Corporation (TTC), a Toyota subsidiary, has a small interest in a joint venture in the country as a result of a merger with Tomen, a trading company, in 2006.
Burma Campaign said the venture involved a state-controlled firm and its vehicles were used by the Burmese military.
Toyota said the venture did not manufacture or sell Toyota vehicles.
"In view of the current sitution in Myanmar, we have conveyed our concerns to TTC and asked them to reconsider their business," the spokesperson added.
Holidays and guidebooks
Tour operator Kuoni, which featured in the list for the first time, said that it only worked with privately-run hotels, minibus and river boat operators in the country.
All contracts were checked by Kuoni's head of corporate responsibility, it said.
Kuoni offers holidays to Burma to Swiss and French customers, but it said the tours were not available in the UK because of a lack of interest.
BBC Worldwide, the commercial arm of the BBC, appeared on the list after it took a majority stake in Lonely Planet last year.
Lonely Planet first published a guide book to the country in 1979.
It said that publishing a guide book to the country "does not of itself represent support or otherwise for the current regime".
"It provides information and lets readers decide for themselves."
Other guide book publishers on the list include Insight Guides and Fodor's, which is published by Random House.
Burma Campaign UK said that pro-democracy leader Aung San Suu Kyi had asked tourists not to visit Burma because it helped fund the regime and gave it legitimacy.
Forced and child labour was used to develop many tourist facilities, it added.
Burma Campaign says more than 100 firms, such as Rolls Royce, British American Tobacco and DHL, have withdrawn from the country since the group began compiling the list six years ago.
Qantas appears on the list because of its controlling stake in Jetstar Asia, which, according to Burma Campaign, flies to the country in partnership with Myanmar Airways International.