The president of the giant public pension fund says the fund's recent decision to change its investment portfolio was a measure to boost domestic stocks.

"We are not deliberately increasing stockholding to embody 'Abenomics,' " Takahiro Mitani, president of the Government Pension Investment Fund, said in an interview Monday, referring to Prime Minister Shinzo Abe's policy mix of aggressive monetary easing, fiscal stimulus and growth-oriented reforms.

On Oct. 31, the GPIF said it will increase the proportion of domestic stocks in its investment portfolio to 25 percent and foreign bonds to 15 percent while slashing its holdings of debt issued at home to 35 percent.