China meted out its biggest fine for price fixing on Wednesday, the latest effort by authorities to provide a level playing field for industries.

The National Development and Reform Commission, a top economic regulator, has levied fines of nearly 670 million yuan ($108 million) against six milk powder companies accused of price fixing and anti-competitive practices.

The six companies are Mead Johnson, Dumex, Abbott, Friesland, Fonterra and Biostime, according to a statement by the commission.

The announcement, which dealt a heavy blow to the dairy industry, follows a recall of milk supplies from Fonterra this week due to possible contamination.

The fines, announced more than a month after the NDRC said it was conducting the antitrust review, coincide with separate pricing investigations into pharmaceutical firms as well as companies involved in gold trading. Those probes have yet to conclude.

The investigations are a reflection of China's intensified efforts to fight price fixing and to regulate the business market.

In response to foreign media accusing China of taking aim at foreign brands to benefit its domestic industries, Commerce Ministry spokesman Shen Danyang said it is groundless to say China's recent investigation into foreign companies specially targets foreign brands.

"Each company in China, whether foreign or local, will receive punishment if it breaches Chinese laws," Shen said. "Instead, these probes will strengthen the investment confidence of transnational companies in China, rather than vice versa."