The Bank of Yokohama and Chiba Bank, two of the country's top regional banks, said Wednesday they have agreed to a business tie-up in a move that could trigger further realignment in the industry.

The move by the biggest and third-biggest regional lenders by assets comes as domestic banks have seen their profitability squeezed by the Bank of Japan's ultralow interest rate policy.

The two banks signed a letter of intent, aiming to launch the partnership within the year in areas such as the sharing of information on mergers and acquisitions, and business successions.