Northwest Bancorp Inc. said Friday that its banking subsidiary, Northwest Savings Bank, will seek to convert from its current two-tier mutual holding company structure to a stock holding company structure.

As part of the reorganization, the bank will undertake a "second-step" offering of new shares of common stock.

Northwest Bancorp said that its board as well as the boards of Northwest Savings and Northwest Bancorp MHC have unanimously adopted a plan of conversion and reorganization. Northwest Bancorp MHC owns about 63 percent of the holding company's outstanding shares.

Under the reorganization, Northwest Bancorp MHC will be merged into Northwest Savings, and its shares in the parent, Northwest Bancorp, will be retired.

Shareholders, other than Northwest Bancorp MHC, will receive shares in a new corporation that will become Northwest Savings' new holding company. A share exchange ratio will be determined based upon an independent appraisal of the new holding company.

The headquarters will remain in Warren. The new holding company will offer its shares of common stock in an amount representing the approximate percentage ownership held by Northwest Bancorp MHC, also based on an appraisal of the company.

The shares will be offered and sold to Northwest Savings' eligible depositors as of June 30, 2008, to Northwest Savings Bank's tax-qualified employee benefit plans, and to the general public.

The conversion would also establish the Northwest Charitable Foundation, an endowment for Northwest Savings Bank's commitment to its communities. Northwest Savings has 167 branches in Pennsylvania, New York, Ohio, Maryland and Florida.

The proposed transactions are subject to approval by shareholders and regulators. Special shareholder meetings are expected to be held at the end of this year's fourth quarter.

The bank said its normal business operations "will continue without interruption during the conversion and offering process," which will not affect terms and conditions of deposit accounts and loans.