TOKYO (Reuters) - Japan Post Insurance and Daiwa Securities Group signed a capital-and-business agreement to cooperate in the asset management field, with the insurer taking a 20% stake in Daiwa's unit, the companies said on Wednesday.

Daiwa Asset Management will issue new shares to Japan Post Insurance, while Daiwa Securities will retain the remaining 80% stake, the three companies said in a joint statement.

Japan Post Insurance will entrust the Daiwa subsidiary with the management of assets, they said.

After years of economic stagnation, the Japanese government is aiming to turn trillions of dollars' worth of savings at Japanese households into investments in stock markets, spurring competition among asset managers.

(Reporting by Chang-Ran Kim; Editing by Subhranshu Sahu)