Anton Oilfield Services Group said on Thursday it planned to strengthen cooperation with Schlumberger Ltd in shale gas development in China after the North American oilfield services and equipment company took a stake in the Hong Kong-listed Chinese company.

Anton's management made the remarks at a conference call to brief media on the company's strategy.

Schlumberger this week acquired about 20.1 percent of Anton Oilfield for an estimated $80 million.

Anton Oilfield, which was founded in 1999 and now has about 1,000 employees, said it first entered into a strategic cooperation agreement with Schlumberger in 2010 in drilling fluids and well-cementing services.

Anton Oilfield, a privately-controlled Chinese oilfield service provider, has said Schlumberger would not be involved in the management of Anton and its cooperation with other business partners would remain unchanged.