Wells Fargo earnings growth accelerated in the fourth quarter, as a rebounding housing market lifted the largest U.S. mortgage lender. But low interest rates pressured margins, and the mortgage pipeline flagged at year-end. The No. 4 U.S. bank by assets earned 91 cents a share, up 25% vs. Q4 2011 and 2 cents more than expected. It was the third quarter in a row of faster growth. Revenue rose 5% to $23.16 billion, beating $21.29