'We express deep sorrow, sincerely apologise, beg for forgiveness for the damage inflicted on children and society by the tainted milk powder,' it said.
'(We) are determined to use this as a warning to put an end to substandard products.'
The message, received by several AFP reporters, claimed to be from 22 Chinese companies found to have sold the tainted milk, including Sanlu, whose former boss was put on trial on Wednesday.
China's milk scandal came to light in September and has had nationwide repercussions with at least six children dying and nearly 300,000 suffering from kidney and urinary problems after they drank milk tainted with melamine.
The industrial chemical, normally used to make plastic, was added to watered-down milk to make it appear higher in protein.
The 22 firms were last week ordered by the government to pay US$160 million (S$232 million) in compensation to the families of babies that died or fell ill.
The compensation work for the victims was now underway, the official Xinhua news agency said on Friday. -- AFP