Merscorp Inc., the parent company of Mortgage Electronic Registration Systems Inc., said R.K. Arnold has retired as chief executive officer and president, and Paul Bognanno will take the job on an interim basis.

Bognanno, former chairman of Radian Guaranty Inc., will lead the search process for a permanent replacement, Reston, Virginia-based Merscorp said in an e-mailed statement.

The MERS system, which Arnold helped develop, has come under fire in courts on the role it has, if any, in home foreclosures. It’s an electronic database of more than half of all the outstanding residential mortgages in the U.S. Merscorp has said it was created by the mortgage industry in 1995 to improve servicing after county offices couldn’t deal with the flood of mortgage assignments.

According to its website, MERS is owned by the largest lenders in the country including Bank of America Corp., Citigroup Inc., JPMorgan Chase & Co. and Wells Fargo & Co., in addition to Fannie Mae and Freddie Mac.