Once a sponsor is identified, it is usually appropriate to make contact with the sponsor. Essentially, this initial contact is to let the sponsor know about the project idea and to find out if it is worthwhile to submit a proposal. Some sponsors have staff who are researchers themselves and can give some helpful input on the project. The Academic Grants Office has agency directories, databases, and other materials that can help in finding the appropriate office or person to contact.
Most foundations discourage phone calls and prefer a letter of inquiry.
A letter of inquiry should be only one or two pages but include concisely all information in the proposal outline. Sample letters of inquiry can be obtained from the Office of Sponsored Projects. Get to know any corporate people on the committee you serve on. Get information from professional associations about any committees that have both university and corporate members. Ask for lists of committees and members.