Hi,
I was halfway through my second year of 457 Visa when the company was sold. My company was growing rapidly and they couldn't operate as a partnership anymore. The company was therefore sold to investors and became a PTY LTD. The company stayed very much the same, same name, same directors, same location. The only thing that changed was the ABN. They re-applied to be an approved sponsor, and then my visa has been transferred to the new ABN ( for your visa to be transfered, you need the company to do a new nomination - no need for a new visa). The company I work for is rather large ($4million turnover / month), so no issue to meet the training benchmark.
Overall, I worked 1 1/2 year under the old ABN & 6 months under the new ABN - 186 visa application lodged under the new ABN - PR granted last week - no question asked, no document requested.
We used a migration agent to do the visa transfer - and the 186 visa application.
Let me know if you need more info.