An anti-corruption watchdog says a new survey of corporations shows mining, oil and gas sector firms rank among the best at disclosing information on revenue, taxes and community contributions while financial companies tend to be the worst.

The findings came in a report on 105 of the world's largest publicly-traded companies released Tuesday by Transparency International.

Norway's Statoil topped the list as the most transparent with a score of 8.3 out of 10 after researchers found it "discloses significant information about its anti-corruption programs, subsidiaries, taxes and profits across its 37 countries of operations."

The Bank of China scored the worst with a 1.1 rating.

Transparency says the 24 financial companies in the report, 13 of which disclosed no data on foreign operations, scored an average of 4.2.