After the merger of five associate banks and the Bharatiya Mahila Bank, top public sector lender State Bank of India (SBI) began operations on Monday with 500 million customers.

The associate banks which merged with the SBI are State Bank of Patiala, State Bank of Bikaner and Jaipur, State Bank Of Hyderabad, State Bank of Mysore and State Bank of Travancore besides the Bharatiya Mahila Bank.

"The SBI opened as 'one bank' today and will continue to operate in the same manner as before post-merger. New products and services will come across more seamlessly," SBI Chairperson Arundhati Bhattacharya told the media.

Bringing cheer to its old customers, SBI also cut the base rate by 15 basis points (bps) to 9.10 per cent with effect from April 1. Earlier, the base rate stood at 9.25 per cent.

The base rate will be effective for those who have raised loans prior to April 1, 2016.

Meanwhile, the marginal cost-based lending rate (MCLR), applicable to those who have raised loans after March 31, 2016, remains unchanged. The one-year MCLR rate is at 8 per cent while the three-year rate stands at 8.15 per cent.

Bhattacharya said the combined entity will enhance productivity, increase operational efficiency, mitigate geographical risks, drive synergies across multiple dimensions and ensure higher levels of customer delight.

With the merger, SBI is now catapulted among the top ranking 50 banks in the world in terms of assets now worth Rs 37,00,000 crore.

It now has a deposit base of over Rs 26,00,000 crore and advances of around Rs 18,50,000 crore, 22,500 branches, including SBI's 20,000 alone, and 58,000 ATMs. SBI also has 191 foreign offices in 36 countries.

The treasuries of the SBI and associates have also been integrated and have now started work as a single entity after the merger.

Now, the bank will undertake various audits before full data integration, which is likely to be completed by April 24 and lead to complete integration of its IT systems, Bhattacharya added.

She said the SBI had made an additional provision of Rs 8,600 crore towards non-performing assets of the associate banks where the cost of funds were higher than SBI.

She assured that no nasty surprises on NPAs were expected in the coming days.

Bhattacharya added that the shares swap of the associates had also been completed and these were listed on the exchanges.

Of the five associates, State Bank of Patiala and State Bank of Hyderabad were not listed entities.

The merger-related blackout of e-channels lasted only three hours and now a seamless integration of web-channels had been achieved, the bank said.