This sounds like you are booking into a trip that many members of your company are going on, perhaps meetings or conference or company gathering? If this is the case, then perhaps your company has booked a block of tickets and seats for the group and you are only booking/buying one of those seats for your self.
Once you have your tickets purchased for both you and your wife, you could try calling the airline to see if they can move your seat out of the company block and into the general seating area next to your wife.
But if your booking is tied to the block, then they might not be able to move you. In this case what you might try doing is picking two reasonable seats in the area outside your block, say an aisle and a middle, put your wife's seat in the middle and then choose a similar aisle seat for your self at the back or front of your company block. That way is the airline is totally unable to change your seat before the flight, you can always ask the person in the aisle seat next to your wife to swap for your aisle seat.