BEIJING -- Three Chinese insurers were required to take measures to rectify overseas investment projects that violated regulations, according to China's insurance regulator.

The insurers were Ping An Insurance (Group) Company of China, New China Life Insurance and China Re Asset Management Company, according to online statements of the China Insurance Regulatory Commission (CIRC) Saturday.

The CIRC said the firms' investment in foreign countries and regions violated official rules published in 2012, without specifying their irregularities.

Chinese insurers are allowed to make investments in 25 developed markets, including the United States and Singapore, as well as 20 emerging markets such as Brazil and Indonesia, according to the CIRC rules on overseas investment of insurance funds.

The firms were asked to make due adjustments and report their rectifications within a month.