G20 finance ministers meeting in Venice on Saturday gave their backing to a "historic" deal on global tax reform, which includes a minimum corporation tax rate of at least 15 percent, a source told AFP.

The ministers also called on other countries to join them in the deal to achieve "a more stable and fairer international tax architecture", said the source.

A framework for global tax reform, including a minimum corporate rate of 15 percent, was agreed this month by 131 countries.

But an endorsement by ministers from the 19 biggest economies plus the European Union will help ensure it becomes a reality following years of negotiation.

The reforms aim to prevent a race to the bottom as countries compete to offer the lowest tax rates to attract investment, with many multinationals as a result paying derisory levels of tax.

(With input from agencies)