This paper examines the effects of bank mergers on systemic and systematic risks, along with other determinants of M&A deals criteria, product and market diversification orientation, crisis threshold and other regulatory and market factors. Results indicate that bank mergers accord with systemic risk. Improvements in operating profit and well-controlled cost of capital can certainly contribute to decreasing systematic risks and capital shortfalls, and consecutively systemic risk contribution. Crossborder deals tend to be sensitive to payment type and prefers cash transactions. Larger acquiring banks decrease systemic risk contribution in crossborder M&As with non-bank financial institutions, and witness profitability (ROA) gain, supporting geographic diversification stability. Capital requirements, activity restrictions, bank concentration and large acquiring banks increase systemic risk contribution of national mergers. Bank mergers with Diversified and Investment FIs targets enhance Productivity (TFP) and overall efficiency but not technical efficiency, contrary to bank-real estate deals where technical efficiency change accompanied lower systemic risk contribution. Unlike ROA, leverage and net operating profit, Sustainability growth rate and ROE significantly improve in all diversifying deals and decreases systemic risk contribution.