I am not exactly sure what you mean by "sponsor" an MBA (sometimes foreign students need a "sponsor" to come to the US), however, if you mean "help pay for" an MBA, there are many companies which will do this. I would suggest you speak to your HR department and ask about reimbursement policies. Usually an employee will need to commit to returning (or staying) at the company for a certain number of years so that the company is getting the benefit of the MBA.
There are also companies which may hire you from an MBA program and agree to pay part of the costs. This was very common when I graduated. Most companies would pay the second year tuition if you took a job offer (especially if you had worked for them as an intern). With a more competitive job market now, this is no longer the norm. But, who knows, it may trend this way again as/if the economy improves!
