Native English Speakers as Managers Over Non-Native Speakers

[Drappuhn]

Hello everyone;
I'm the manager of professional development training for a multinational firm based in Chicago. Within our firm, many managers who are native English speakers have non-native speakers on their professional staff. Many of these non-native speakers hold advanced degrees in chemistry, biology, and other technical areas, and their diminished abilities to be clearly understood negatively affects their careers.
The managers would like to coach their employees regarding their ability to speak English, but don't know where to start. Using myself as an example, I might tell a member of my staff that the way they just spoke a particular word was incorrect - but I would not be able to help them hear a broader pattern within their accent, or help them discern a rule for broader application.
I would like to bring in a training program for managers - starting with a short overview (i.e., 2 hours) that would be informative, yet at the same time, possibly encourage those same managers to take part in a longer training program.
I am having difficulty locating such a program ... my web searches have come up short. Can anyone offer any suggestions for a firm that offers such programs?
Thanks!