Breaking into the FO

Hi Guys, long time lurker first time poster.

Bit of background; I'm currently in my penultimate year at a semi target EU based Uni. I have a 12 month academic internship in Finance (MO/BO), at a medium sized asset servicing firm. My overall goal is to secure a FO IB job once I graduate (most likely post-masters). For the coming summer I have accepted a Big 4 FS Assurance internship offer (boring I know). Today I was offered a MO/BO operations role in a BB which would require me reneging on my current contract. I live & will work in a relatively small city so reputation matters. (I hope to move to London once I complete my undergrad & masters).

While I know the Big 4 & BB operations internships are miles from my end goal, is it worth reneging on my contract with the Big 4 firm and accepting the operations gig? Neither job will be overly interesting or challenging and the only benefits I can see for taking the MO/BO job would be a chance to network and having the BB's brand on my CV. (Please note the networking opportunity's within the bank will be limited as the office I will be in only has BO & MO staff).

Thanks in advance.