MANILA - The Philippines is reviewing the performance of a genetically modified Bt corn introduced by Monsanto Co. for commercial cultivation in the country, the Department of Agriculture said Thursday.

The review will determine whether the department will issue another-five year permit for the commercial planting of Monsanto's Bt corn, said Joel Rudinas, director of the Bureau of Plant Industry, an agency under the agriculture department.

"The review will zero in on the claimed benefit of the event, which is to contain corn borer and the possible implication or observed actions in the environment," Rudinas said.

A scientific and technical review panel, or STRP, is conducting the review, he said.

A five-year government authority issued by the agriculture department in December 2002 on the use of Bt corn will expire early next month.

Bt, or bacillus thuriengensis, corn is a genetically modified seed variety resistant to the corn borer pest, which damages up to 80% of infested corn farmlands.

So far this year, around 200,000 hectares have been planted to Bt corn, up from around 130,000 hectares in 2006.