For BB&T, Jefferies estimates earnings of $3.05 a share for both 2013 and 2014. Under the scenario of mortgage gain-on-sale margins reverting to 2011 levels, Usdin estimates that the company's earnings would decline by 23 cents for 2013 and 14 cents for 2014.

Usdin estimates that Fifth Third will earn $1.65 a share this year and in 2014. If gains-on-sale margins declined to 2011 levels, the analyst estimates the company's earnings would be lowered by $0.12 for 2013 and $0.07 for 2014.

-- Written by Philip van Doorn in Jupiter, Fla.

>Contact by Email.

Philip W. van Doorn is a member of TheStreet's banking and finance team, commenting on industry and regulatory trends. He previously served as the senior analyst for TheStreet.com Ratings, responsible for assigning financial strength ratings to banks and savings and loan institutions. Mr. van Doorn previously served as a loan operations officer at Riverside National Bank in Fort Pierce, Fla., and as a credit analyst at the Federal Home Loan Bank of New York, where he monitored banks in New York, New Jersey and Puerto Rico. Mr. van Doorn has additional experience in the mutual fund and computer software industries. He holds a bachelor of science in business administration from Long Island University.

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