UPDATE 1-MGIC defers certain interest payments; shares fall

* Interest on certain debentures due Oct. 1 deferred

* Says deferred payment to Oct. 1 2019

* Shares down 6 pct

Sept 14 (Reuters) - MGIC Investment Corp (MTG.N) said in a regulatory filing that it was deferring interest payments on certain debentures which were due on Oct. 1, sending its shares down as much as 6 percent.

The interest payment on its 9 percent convertible junior subordinated debentures due 2063 has been deferred to Oct. 1, 2019, the largest U.S. mortgage insurer said.

Mortgage insurers like MGIC and rivals PMI Group Inc PMI.N and Radian Group Inc (RDN.N) have suffered huge losses from backing subprime bonds and mortgages that saw a surge in defaults as U.S. credit and housing markets worsened.

Shares of the Milwaukee-based company were down 5 percent at $9.24 Monday morning on the New York Stock Exchange. (Reporting by Brenton Cordeiro in Bangalore; Editing by Unnikrishnan Nair)