IT director proposal?

Present your request from a business perspective:

I would like to propose some organizational changes in our department. I currently manage systems X, Y and Z as well as a team of ##. Under my management we have acheived the following results:
Result A
Result B
Result C

I am interested in taking on more responsibility within the organization as a director. I have spent time developing leadership skills within my team and feel that we have several highly qualified candidates to take over my current responsibilities. This will allow me to re-focus my energy on addressing the challenges we face:
Challenge A
Challenge B
Challenge C

You should start with your successes, be prepared with candidates to take over your role, finish by demonstrating your understanding of the bigger picture, and state clearly that you are looking for the director position. If you don't state it specifically you face the chance of getting more responsibility without a promotion. If he/she says "No" ask for recommendations - "what actions do I need to take to become your ideal candidate for director?"

Good luck.

Rachel