China's central bank has acquired a stake of just more than 0.7 percent in Drax , which runs Britain's biggest coal-fired power station, the UK's Daily Telegraph reported on Tuesday.

The People's Bank of China built its stake over the past year, in what would be the latest case of the central bank quietly striking out on its own to invest tiny portions of the country's $1.81 trillion in foreign exchange reserves.

A Drax spokesman said the company was aware of the investment, which amounted to about 18 million pounds ($32.22 million), and welcomed all long-term investors, the Daily Telegraph reported.

The press office of the central bank said it had no comment.

China last year established a $200 billion sovereign wealth fund, the China Investment Corp, to increase returns on its forex holdings, and it has taken high-profile stakes in Morgan Stanley and Blackstone Group.