Top Wells Fargo (WFC) executives downplayed concerns about the Federal Housing Administration despite mounting mortgage delinquencies on the bank's balance sheet. Wells Fargo home loans insured by the FHA or guaranteed by Veterans Affairs began climbing in the back half of 2011. By the end of the fourth quarter, $19.2 billion of these loans were more than 90 days past due, up from $16.4 billion the previous quarter and $14.7 billion at Dec. 31, 2010, according to the bank's financial statements released Tuesday. The growing delinquencies stoked concern as the FHA Mutual Mortgage Insurance Fund capital ratio continues to head in the wrong direction. According to an annual report sent to Congress in November, the fund slipped to 0.24% in fiscal 2011, down from 0.5% last year. Federal law mandates the ratio remain higher than 2%, which it hasn't been since 2009. The FHA said it was highly unlikely the fund would need a bailout. But mortgage servicers reported nearly 690,000 FHA-insured mortgages in serious default for a rate of 9.3% as of Nov. 30, according to the latest available data. It's up from a 2011 low default rate of 8.17% in May. In a conference call with investors Tuesday, Wells Fargo executives tried to temper concerns over their FHA numbers. The bank claimed the increase was "due primarily to growth in the FHA/VA portfolio over the past two years and the subsequent seasoning of those loans." "What you're seeing is that we're a very large mortgage lender in this country," Chief Financial Officer Tim Sloan said. "Because our FHA and VA lending has increased since 2008, there will be a natural increase (in delinquencies). But they're actually performing better. It's just that we're a bigger lender." "We've not seen any change in how they'll guarantee their mortgages," CEO John Stumpf added. Wells Fargo became the top FHA and VA mortgage originator in the country after 2010 — a spot it held off and on over the past decade — originating more than $112 billion worth of these guaranteed mortgages that year. Write to Jon Prior. Follow him on Twitter @JonAPrior.