Using the same brand worldwide helps a firm develop a global image, but may not always be possible because of language differences or because the firm has acquired a locally branded product.
Country-of-origin can also be a factor in branding.
A global brand can help a company overcome negative country-of-origin images, but keep in mind that images can change.
Note also that the advantages of a well-known brand can be negated if the brand becomes a generic term.