Mortgages accounted for nearly half of the complaints received by the Consumer Financial Protection Agency (CFPB) in its first year-and-a-half of operation, the agency has reported.

Some 131,000 consumer complaints have been received by the agency since it was established in July 2011, of which 63,700, or 48 percent, have had to do with mortgages. Credit cards were the next most common complaint, accounting for 30,600 reports, or 23 percent of all reported complaints.

The figures were included with last week's release of a searchable public database of complaints the agency received in 2012.

"By sharing these complaints with the public, we are creating greater transparency in consumer financial products and services," said Richard Cordray, CFPB director. "The database is good for consumers and it is also good for honest businesses. We believe the marketplace of ideas can do great things with this data."

Most complaints related to debt problems

The majority of mortgage-related complaints, 61 percent, had to do with situations where consumers were having difficulty meeting their payments, such as foreclosures, collections or loan modifications. In general, according to the CFPB, consumers making such complaints were seeking to reach an agreement with their mortgage companies about foreclosure alternatives.

One of the most common complaints had to do with the shelf life of certain documents required for loan modifications. For example, documents verifying income are valid for only 60 days, but the process of evaluating borrowers for a loan modification would often run longer than that, meaning the documents had to be resubmitted, sometimes multiple times.

A few receive financial compensation

Other common mortgage-related complaints related to making payments, with loan servicing, payments or escrow accounts cited in 22 percent of cases. Only 7 percent of mortgage complaints related to the application process.

Just under 90 percent of mortgage complaints received were referred to the lenders involved for review and response, with the rest either forwarded to other federal agencies for action or pending further review.

Of the mortgage complaints referred to lenders for review, about 3 percent (1,800) resulted in payments to consumers averaging $425. In more than one case in five, consumers continued to dispute the response offered by their mortgage company.