The aim of the partnership is to find ways to "maximize Pioneer's overall franchise value", according to a UniCredit statement.
Insider sources told Bloomberg that Bank of America Merrill Lynch will help the European company explore the possibility of either selling the unit, finding a new co-owner or raising funds through an initial public offering.
The announcement came as UniCredit reported a profit of â¬520 million ($658 million) in its results for the first quarter of the year.
Its performance was better than had been predicted by Bloomberg analysts, who had forecast the financial institution was on course to record a net income figure in the region of â¬364 million.
Earlier this year, UniCredit sold off shares at a 29 per cent discount in a bid to raise around â¬4 billion in capital.
By Claire Archer