Japan's stock rout in the quarter through March spurred the first loss for the world's biggest pension fund in almost two years, just as it moves toward buying more equities.

The Government Pension Investment Fund lost 0.8 percent on its investments in the final three months of the fiscal year, trimming assets under management to ¥126.6 trillion ($1.2 trillion), GPIF said in a statement Friday.

The quarterly loss was the first since April-June 2012 and reflected a 7.1 percent drop in GPIF's Japanese shares as the Topix posted the steepest slide among 24 developed markets. The equity measure then rebounded 6.9 percent through the end of last week.