Sales agents register. Find a sales agent for your product. Charged for services but useful information about what sales agents do and how they work. - Sales Agent Services Worldwide

List of sales agents worldwide. (These are for overseas sales agents)

Manufacturers' Agents Association

Association of commercial (or commission or sales) agents for manufacturing companies as well as distributors. Offers an agent finding service (for a fee).

Some trade associations may include agents and may be able to source agents for example:
UK Fashion and Textiles Association