Wells Fargo CFO Tim Sloan said mortgage lending volume will likely decline as refinancing of existing mortgages slows and isn’t offset by mortgages for home purchases. Investors of the nation’s largest mortgage lender have been concerned about how the bank’s mortgage business is doing. During an investor conference today, Sloan said the San Francisco-based bank has a “good opportunity” to refinance eligible homeowners in its $1.9 trillion mortgage servicing portfolio, Reuters reported. Sloan…