India Ratings & Research (Ind-Ra) has affirmed Union Bank of India's long-term issuer rating at 'IND AA+'. The outlook is stable.

The affirmation reflects Ind-Ra's expectation of strong support from the government of India (GoI), if required by Union Bank, in the event of a systemic crisis.

The expectation is based on the bank's systemic importance as it is among the 10 largest commercial banks in India and the country's sixth-largest public sector bank in terms of assets and systems' deposits.

The bank has a pan-India franchise (3,881 branches) and majority government ownership.

The bank has received regular capital injections in the last four years from GoI and Life Insurance Corporation. GoI infused Rs 5 billion of equity into the bank in 3QFY14.

Shares of the company gained Rs 6.95, or 3.65%, to settle at Rs 197.40 at the BSE (Tuesday).