The Ohio-based Fifth Third Bancorp (NASDAQ:FITB) said this morning that third-quarter pre-tax earnings grew by $101 million, or 20%, over the year-ago period thanks in large part to a $91-million gain from the sale of its stake in Vanitv (NYSE:WP), which provides payment-processing services to U.S. companies.

"Fifth Third reported solid third-quarter results, reflecting our continued focus on revenue generation as well as expense discipline," said chief executive officer Kevin Kabat.

The regional bank's performance parallels that of its competitors. If you exclude the Vantiv transaction -- impacts of which were felt in both the third quarter of this year and the year-ago period -- net revenue fell by $67 million, or 4.2%, on a year-over-year basis.

Of this, $10 million came from a decline in net interest income, as an improvement in its cost of funds wasn't enough to offset the negative trend in its yield on earning assets. The remaining $57 million fall -- this, again, is excluding the Vantiv sale -- came from a drop in fee-based revenue.

In a now-familiar storyline, income from mortgage banking was particularly hard hit, as higher interest rates dissuaded homeowners from refinancing their existing home loans. For the three months ended Sept. 30, income from mortgage operations plummeted by $79 million, or 40%.

The one saving grace for Fifth Third was its performance in terms of expenses. Operating expenses dropped by $47 million, or 5%, compared to the third quarter of 2012. Though, it's worth pointing out that $39 million of the improvement related to a positive trend in representation and warranties reserves. It built reserves by $24 million in the same quarter last year, while this year it released $15 million.

And adding a final boost to the bottom line, Fifth Third set aside $14 million less this year for future loan losses. This comes on the heels of an improvement virtually across the board in credit quality at the nation's largest banks.

At the time of writing, shares of the Ohio-based bank are up by 2.7%.

John Maxfield has no position in any stocks mentioned. The Motley Fool owns shares of Fifth Third Bancorp. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.