On Friday, Mitsubishi UFJ Trust and Banking announced a strategic business alliance with AMP Capital Investors, including a 15% stake in its parent, AMP Capital Group, for A$425 million and one seat on the board.

AMP Capital notes this will give the Australian firm "access to around 80% of Japan's institutional investors and approximately 14% of Japan's retail and high-net worth banking networks", as well as to securities branches.

However, this access will be indirect. Anthony Fasso, CEO at AMP Capital International, notes this is a sub-advisory relationship.

But it is an unusually close sub-advisory deal, and one that may come to count for something more substantial than other such arrangements that have recently come to define the most effective way for global money managers to tap Japanese assets.

Japanese institutional money, after a decade of moving assets to investment management companies and away from stodgy gatekeepers (sokanji) such as trust banks and insurance companies, have reverted to old habits. In a longstanding environment in which local interest rates are ultra-low and international exposures are undermined by the strong yen, Japanese pension funds and other investors have put far more assets back with trust banks.

Trust banks package consulting services together with passive investment strategies, pension services and, of course, corporate banking relationships at the parent company level.

This is why Japanese trust banks have seen their assets under management swell. MUFJ Trust and Banking is, in fact, the largest manager of assets sourced from the Asia-Pacific region, according to the December edition of AsianInvestor magazine. It runs $369.8 billion of assets, all sourced locally, up 12.5% year-on-year.

However, trust banks can't do it all, and their clients still need solid, actively managed investment products from abroad, both to diversify and to earn a return. So even as trust banks hoover up assets, they have turned increasingly to sub-advisory relationships with global managers.

MUFJ Trust and Banking already has many such relationships, some longstanding. These include Pimco for fixed income, Baillie Gifford and Aberdeen Asset Management for equities, and several firms for hedge funds or other alternative strategies, including Guggenheim Partners, MC Titan, Northern Trust Global Investments and UBS Global Asset Management.

Nor is MUFJ alone. Other major trust banks and some of their known or suspected relationships for institutional and retail distribution include:

Sumitomo Trust & Banking ($312 billion of AUM) with AllianceBernstein for equities, Wellington for fixed income and for hedge funds, FRM for funds of hedge funds, Sloan Robinson for hedge funds, and AMP Capital for infrastructure.

Chuo Mitsui Trust & Banking ($289 billion) with Standard Life Investments for equities, Baring Asset Management for emerging-market equities, Wellington for emerging-market debt, Mesirow Financial and Lyxor Asset Management for hedge funds.

Mizuho Trust & Banking ($285 billion) with AllianceBernstein and MFS Asset Management for equities, Comgest for emerging-market equities, BlackRock for fixed income, Blue Bay for emerging-market debt, and Goldman Sachs Asset Management and Monex Global for hedge funds.

Resona Bank (AUM undisclosed) with Analytic Investors for enhanced indexed equities, Northern Trust for multi-manager, Amundi for socially responsible investments in equities and for hedge funds, AllianceBernstein and Schroders for emerging-market equities, and AllianceBernstein, Brown Brothers Harriman and Mondrian for fixed income.

So in this vein, AMP's deal is following a well-honed path. Indeed, AMP already provides a strategy to Sumitomo. Fasso says the deal with MUFJ will allow AMP to retain existing third-party distribution arrangements for retail products. These channels include Bank of Tokyo Mitsubishi UFJ, Mitsubishi UFJ Morgan Stanley Securities and MUFG's network of third-party banking and securities distributors.

AMP Capital has already raised around A$5.5 billion of client assets from Japan in the past few years, it says.

However the two firms will forge an exclusive relationship for providing AMP products to Japanese institutional investors, including public and private vehicles for real estate and infrastructure.

Jo McBride, an industry blogger, notes such products continue to enjoy strong demand in Japan as its aging pensioners require steady income.

This deal is also not unique in having a Japanese bank take a stake in its foreign partner: MUFJ Trust and Banking did the same with regard to Aberdeen, taking a 9.9% stake in 2008 that it later raised to 16%.

Ownership stakes, however, are not a promise of distribution. MUFJ Group, the trust bank's parent, took a 21% stake in Morgan Stanley in September 2008 (now raised to 22.4%). At the time this raised speculation that Morgan Stanley Investment Management could leverage this into boosting its business in Japan, particularly in the retail space, but efforts at collaboration came to naught.