Penang has slammed new Bank Negara guidelines requiring exporters to convert 75 percent of their proceeds into ringgit.

Chief Minister Lim Guan Eng said such measures undermined investors' confidence in the country.

He said multinational companies had complained about the matter.

"We are concerned that the environment for investment will not be favorable to Malaysia," Lim said at a press conference.

"We understand Bank Negara wants to do this to protect the falling ringgit but it does not cure the sickness, only symptoms," he added.

Lim urged Bank Negara to abolish the new policy which was announced on Dec 5, saying it might impact on the country's foreign direct investments.

Although the policy was introduced to stabilise the country's falling ringgit, Lim said this would only impact on investments to the country.

Lim also urged the Ministry of International Trade and Industry to review the policy.

"Instead of requiring exporters to convert three-quarters of their earnings, why not 25 percent?" Lim said.