Leading Myanmar firms called on China Wednesday to improve investment practices in its impoverished neighbour, amid increasing scrutiny of Beijing's sometimes controversial projects.

China is a long-term ally of former military-ruled Myanmar. It accounts for the lion's share of the country's foreign direct investment -- about 33 percent -- and is considered a crucial trading partner.

But a series of political reforms have seen Western sanctions against Myanmar swept away, raising hopes of a boom in international investment.

"There are not only Chinese businesses here now. The message we want to give is that international countries are coming," said Aye Lwin of the Union of Myanmar Federation of Chambers of Commerce and Industry.

Speaking to a visiting Chinese business delegation, he said it was an "important time" for investors from across the border, urging them to abide by "international standards" and act in an environmentally and socially responsible manner.

During Myanmar's junta era the ruling generals, tarnished by mounting human rights abuses, were shielded from international opprobrium by China's economic might and its UN Security Council veto.

In return, Beijing was assured of a relatively stable neighbour and access to Myanmar's abundant natural resources such as metals, timber and gemstones, as well as involvement in numerous hydropower projects.

Observers say fears over the sheer scale of Beijing's power helped spur the junta into relinquishing their grip, making way for a quasi-civilian regime in 2011.

Reformist President Thein Sein quickly asserted his independence, ordering the suspension of work on a hugely unpopular Chinese-backed mega-dam in 2011.

Myanmar in July revised a controversial copper mine deal with a Chinese company after a series of protests against the project that triggered a violent police crackdown.