SEOUL (Reuters) - A worker at a South Korean plant of General Motors (GM.N) was found dead in a suspected suicide after filing for a voluntary redundancy program of the U.S. carmaker's ailing unit, union officials and police said on Sunday.

GM plans to shut down its Gunsan plant by May and almost 2,500 workers, or about 15 percent of the staff, have applied for the redundancy package offered as part of a restructuring of its operations.

The death of the 47-year-old worker in his home was reported to police around 4:30 p.m. on Saturday, and the suspected suicide is being investigated, a police official said.

If proven, it would be the first suicide reported from the plant ahead of the planned shutdown.

A spokesman for GM Korea said it was also looking into the case.

In March, GM's South Korean union did not demand a pay rise and bonuses for the first time during annual wage talks, but instead asked it to provide a future production plan and job security.

The firm has proposed a base wage freeze and no bonuses this year, besides a suspension of some worker benefits, including school tuition for employees' children.

(Reporting by Jane Chung and Hyunjoo Jin; Editing by Clarence Fernandez)