To form a three-digit number divisible by three, the sum of its digits must be divisible by three.
The possible combinations of three digits from the given set are:
- 2, 3, 4
- 2, 3, 5
- 2, 3, 6
- 2, 4, 5
- 2, 4, 6
- 2, 5, 6
- 3, 4, 5
- 3, 4, 6
- 3, 5, 6
- 4, 5, 6
For each combination, we can arrange the digits in $3! = 6$ ways.
Therefore, there are $10 \times 6 = \boxed{60}$ three-digit numbers divisible by three that can be formed using the digits 2, 3, 4, 5, and 6 without repetition.