A coalition of climate groups filed shareholder proposals with Japan's top three banks, including Mitsubishi UFJ Financial Group, calling for stricter board oversight of climate-related risks, people familiar with the matter said.

The proposals from Australia's Market Forces, Japan's Kiko Network and a representative of Rainforest Action Network mark the first time climate groups have targeted the boards of the banks as a way to pressure the lenders on climate change.

The proposals focus on board oversight of climate-related business risks and seek to make the megabanks — Mitsubishi UFJ, Sumitomo Mitsui Financial Group and Mizuho Financial Group — disclose how they evaluate director competency for such oversight, the people said on condition of anonymity as the information is not yet public.