China has urged domestic companies to avoid "irrational" overseas investments following a record-setting buying spree that has worried authorities about capital outflows and rash spending.

The rebuke carried by the Xinhua news agency did not single out particular firms but highlighted areas such as sports, hotels and entertainment where there have been major deals involving Chinese groups.

"We advise such companies to make cautious decisions," according to a joint statement issued by the Ministry of Commerce and other agencies and published late Tuesday.

"Regulatory departments are also closely watching the irrational tendency in overseas investment in fields including real estate, hotels, cinemas, entertainment, and sports clubs."

The wave of overseas investment this year has complicated efforts by Beijing to stem capital outflows, which are putting downward pressure on the yuan.

Chinese mergers and acquisitions abroad in the first eight months of the year reached $61.7 billion, surpassing those for all of 2015, official data showed recently.

Among the more high-profile deals are Wanda Group's purchase of Hollywood studio Legendary for $3.5 billion, as well as London-based Odeon & UCI cinema group in a deal worth around $1.2 billion.

The Chinese property-to-entertainment conglomerate also paid more than one billion euros for Swiss-based Infront Sports & Media.

Appliance giant Midea took over leading German robotics firm Kuka for $5 billion, and insurer-turned-hotelier Anbang paid $6.5 billion for 16 luxury properties from hedge fund Blackstone.

Chinese companies have increasingly gone abroad for investment opportunities as domestic growth slows and the government has encouraged firms to seek technology, resources and market access overseas.

"One of the reasons regulators are doing this is because the yuan (currency) has been under depreciation pressure and it is hard to control capital outflows," said Li Jiachao, marketing director for mergers and acquisitions advisory firm DealGlobe.

China's foreign exchange reserves plunged by $69 billion in November to $3.05 trillion, its fifth straight monthly contraction and the largest month-on-month decline since January.