Commonwealth Securities/Colonial Margin Lending and Goldman Sachs JBWere Margin Lending have received top marks in a new survey on margin lending providers.

The companies received a five-star rating for both the share investor and managed fund investor categories from rating agency Canstar Cannex.

St George received a five-star rating in the share investor category.

The practice of margin lending has become controversial in the financial crisis after many investors received margin calls, forcing them to make cash contributions or sell part of a share portfolio against the current low prices.

Some investors borrowed against the value of their homes and had to sell their houses to fulfil the obligations of the lending contract.

Although borrowing money to invest is not without risks margin lending should not be vilified, Canstar Cannex financial analyst Frank Lopez said.

"Unfortunately, margin loans seem to have taken the rap for bad investments when, in all likelihood, it's the financial advice that should be questioned," Lopez said.

Margin lending is not regulated in Australia but the government announced plans in January this year to regulate the industry through ASIC, which aims to help investors better understand the risks involved.

Canstar welcomes the proposals. "Any move to make the overall lending structure more transparent and advice more appropriate will protect investors using margin loans, and this can only be a good thing," Lopez said.