MANILA -- Profits-based royalty and a windfall profits tax, as passed by a House of Representatives committee, is the "most equitable manner" to raise revenues, the Chamber of Mines said Tuesday.

Further taxes on mining may not be warranted, since the first tranche of tax reforms doubled doubled excise duties to 4 percent of gross revenues starting January, the Chamber said.

"By adopting this, the structure will help sustain existing mining operations and hopefully encourage quality investments in the hugely untapped Philippine minerals sector," it said in a statement.

A similar profits-based royalty scheme is used in Canada, Peru, Chile and South Africa, it said.

The House Ways and Means Committee passed the profits-based royalty scheme on Monday, as Congress resumed sessions.

• House approves bill on mining revenue reforms