Fifth Third Bancorp's (NASDAQ:FITB) earnings announcement is coming Thursday morning, and investors are facing a big question: Will Kevin Kabat and crew deliver good news? Or should investors be fretting the upcoming release?

Fear not, Fool!
Last quarter turned out to be a so-so quarter for the Cincinnati bank, with it reporting earnings in line with expectations. However, the bank didn't quite reach its full potential, experiencing numerous one-time charges that directly affected the bottom line by at least $66 million. Investors are hoping that these charges are indeed of the "one-time" variety, and that the bank can return to meeting its potential. However, like with most of the other banks reporting over the next few weeks, there are other issues to worryy about.

This might start sounding like a broken record, but investors interested in banks should be particularly wary of declines in net interest margin this earnings season. I'm even willing to predict that if a bank sees an increase in this ever-important metric, it will shoot up $4-%5 that day.

Luckily, one area that Fifth Third was strong in last quarter was its mortgage lending, with mortgage lending up 16% and commercial and industrial lending up 15% . If there is one thing banks can do to combat declining interest margins, it is increase lending volume, with associated fees filling in the gaps of potentially lost income. Should Fifth Third continue to increase its lending, investors might not have to worry that much about one of the biggest issues facing banks these days.

Easy numbers to digest
Analysts are expecting big things from the bottom line at Fifth Third, with total earnings for the year expected at $1.62 per share. This would be a 36% increase from 2011. Analysts also see around 6.5% growth in annual revenue for the bank, expecting $6.4 billion. If Fifth Third can meet or exceed these expectations, 2013 would be off to a very strong start for the bank, and investors would stand to benefit going forward.

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