Credit unions posted a significant increase in mortgage production volume during the first quarter of 2011, compared to the same period last year, but the industry has not yet broken through to a broader role in the market. Federally insured credit unions originated $21.5 billion in home mortgages during the first three months of the year, up 16.6 percent from a year ago, according to data from the National Credit Union Administration. But that was down 35.7 percent from the $33.5 billion that credit unions originated in the fourth quarter of 2010. The credit union share of the total mortgage market held steady at 6.6 percent of total... [Includes two data charts]