They are both fine.
Interested in Language
When you introduce yourself to your audience at the beginning of your presentation,
1. I work for Company A.
2. I'm working for Company A.
I think 1 is correct. How about 2?
(This is not a case where the speaker says something like "I've been working for Company A for XX years. He just wants to say which company he works for.)
2 might suggest that this is not a permanent job, though.
Or that it is a job that he or she only recently started.
I'm not a teacher, but I write for a living. Please don't ask me about 2nd conditionals, but I'm a safe bet for what reads well in (American) English.