The Philippines' Ombudsman Merceditas Gutierrez resigned on Friday amid a swirl of controversy and criticism in her office's handling of corruption cases filed against individuals with close links to former president Gloria Macapagal Arroyo.

Mrs Gutierrez personally handed in her resignation letter to President Benigno S. Aquino III around mid-morning of Friday. The president accepted the resignation.

The resignation will take effect on May 6, just three days before the Philippine Senate begins its trial on her impeachment that the House of Representatives of the bicameral legislature approved last March 22.

Among those who closely followed the ombudsman's case, the business sector had paid particular attention for any indications of the Aquino administration's ability to pursue its proclaimed war against corruption, and its supposed impact on investor confidence in the Philippines.

During the impeachment hearings at the House, Mrs Gutierrez persistently refused to appear before the congressmen and instead maintained a feisty stand in criticizing the proceedings.

The charges against her in the impeachment move centered around her alleged dismal performance that resulted in a low conviction rate during her term that started in 2005, and accusations of inaction on major cases of corruption filed against known political allies of former president Arroyo, now a member of the House.

Speculation about Mrs Gutierrez's plans regarding the impeachment trial escalated following her newspaper column where she said that "resignation... is supposedly the better of few options available to me today."

"If I persist in fighting the charges leveled against me and I lose," the embattled ombudsman wrote further, "I lose not only my retirement benefits, the opportunity to again serve government in equally dignified but less taxing capacities, but will also reap the shame of being the first Ombudsman to have been forcibly removed from office."

"But in the depths of my being, I see that as capitulation to false charges," she said.

She announced in a media briefing her resignation Friday afternoon. Mrs Gutierrez maintained that "all the accusations against me are groundless."