BANGKOK, Thailand — Eleven microfinance groups that together serve nearly 26 million people agreed Monday to publicly report their annual interest rates, a move many hope will empower the world's poorest borrowers as the once-charitable sector becomes increasingly commercialized.

"If you are making profits you are moving into the same mental mindset as loan sharks," Nobel Peace Prize winner Muhammad Yunus told The Associated Press in a telephone interview from Bali, Indonesia, where he is attending the 11th annual Microcredit Summit Campaign conference that opened Monday.

When Mr. Yunus began making $27 (U.S.) loans to women in Bangladesh three decades ago, he hoped to rescue the poor from usury. The new language of microfinance, which turns on words like "return on equity," today weighs heavily on his mind.

He believes interest rates should be set to cover costs, not maximize profits.

"Microcredit is about helping poor people get out of poverty," said Mr. Yunus, whose pioneering bank, Grameen Bank, has already signed on to the new MicroFinance Transparency initiative.

Grameen is owned by the poor borrowers it serves, and sustains itself with local deposits. The bank reported a narrow profit of 106.9 million Bangladeshi takas ($1.6-million) on revenue of 10.6 billion takas ($155-million) in 2007.

Grameen charges a maximum interest rate, non-compounded, of 20 per cent a year. Beggars pay no interest, and total interest payments can never exceed the principal of the loan.

The rush of new entrants into the microcredit market has created a welter of offerings, but lack of standardized reporting makes it hard for borrowers to figure out how to get the best deal.

"Clients are at a significant disadvantage," said MicroFinance Transparency founder Charles Waterfield.

He aims to bring truth-in-lending standards to the developing world, by publishing standardized annual interest rates on the Internet. The data from lending institutions will be self-reported.

The initiative, a U.S. non-profit, is still cementing funding and plans to start publishing country-specific data on its website in October.

The push for disclosure comes at a time of intense debate within the field, which pits privatization advocates against those who believe you can either save the world or make a buck – but not do both at the same time.

Members of the pro-market faction argue that civic-mindedness alone will never draw enough capital to serve the billion people who want rudimentary banking services. Profitability is the key to sustainability, they say.

Those against commercialization fear the microcredit movement is losing its soul, prioritizing investors over the world's farmers, sheepherders and street vendors, many of whom struggle by on less than a dollar a day.

Microfinance, for profit or not, is booming. According to Deutsche Bank, the volume of microfinance loans hit $25-billion in 2007, up from $4-billion in 2001, and another $250-billion is still needed. The bank expects that private investors will pour $20-billion into microfinance institutions in 2015 – 10 times more than they did in 2006.

Many groups that started as non-profits have become for-profit, and a plethora of microfinance investment funds, targeted at institutions and individuals, have opened in the last few years.

Citigroup Inc., Credit Suisse Group, Deutsche Bank, and Morgan Stanley have all entered the microfinance market, either providing direct funding, backing investment funds or securitizing debt, and private equity investors have also started to pile in, according to the World Bank's CGAP, a microfinance research group.

"You are seeing more and more financially driven investors going into this market," Eric Savage, managing director of Unitus Capital, a new for-profit firm that will help microfinance groups raise capital, said by phone from Bangalore, India.

Mr. Savage said the subprime crisis may give microfinance a further boost as investors seek diversification, and that tightening credit has so far had a "quite muted" effect on loans to microfinance institutions.