Background Check - Firm name partly mispelled !!

Hello guys,

I am very worried about a potentially serious issue and would like to see what are your opinions on the fact and what would you recommend me to do.

I have successfully landed a 1-year placement at a BB bank. As you might know, the offer is conditional upon positive background check.

Well, the problem is this:

In the past, I have worked for 2 months in a part-time (unpaid) position for firm XXX YYYY (not a big company) in a foreign country (not a very well known one). However, on my CV, I partly misspelled the name of the company as ZZ YYYY.

Now, I am oscillating between:

1) calling them and confessing my incompetence in writing a company's name and risking raising further suspicions while also feeling like an idiot (well, I must confess that i was in this case, but just don't want to show off)

2) completing the employment history form with the misspelled name in the hope that they might not verify this in particular or that if they do they might not consider it as grave as to question my credibility (given that the name was just partly misspelled - and does not coincidentally represent another company, and with address, dates, references and position being 100% true).

I appreciate your opinions.

Thanks!

P.S.: I mention the company hires a third party for doing the background check.