Fbr wins Edison award in usa, page-21

Hi Adent,

Investopedia is your best friend for a question like that. I'll save you a click though:
There are numerous advantages of dual listing - Companies get access to a larger pool of potential investors, which can be beneficial for investors as well. For example, many Australian and Canadian resource companies list their shares on European exchanges because of substantial investor interest, partly due to the relative paucity of local resource companies.

Dual listing improves a company’s share liquidity and its public profile because the shares trade on more than one market. Dual listing also enables a company to diversify its capital-raising activities, rather than being reliant only on its domestic market.

Among the drawbacks is that dual listing is expensive due to the costs involved in the initial listing and ongoing listing expenses. Differing regulatory and accounting standards may also necessitate the need for additional legal and finance staff. Dual listing could place more demands on management as well, given the additional time required to communicate with investors in the second jurisdiction through road shows, for example.