In a two-way tie up with two leading private sector banks, State Bank of India has forged one of the biggest alliances to share ATM networks.

Following the signing of a memorandum of understanding, the customers of country's largest commercial bank and ICICI Bank can access each other's ATM network for a small fee, a SBI release said in Mumbai on Tuesday adding that its customers will also enjoy similar benefits on a reciprocal basis with HDFC Bank.

"We are forming this alliance, which will herald us ahead of all such partnerships with a shared ATM network of around 4,500 ATMs in the country," a senior SBI official had said.

SBI has its own network of 2,000 ATMs, which would be increased to 3,000 by the end of the year, he added.

The signing ceremony for the ATM partnership took place at the SBI headquarters in the presence of SBI chairman A K Purwar, HDFC chairman Deepak Parekh, HDFC Bank chairman Jagdish Capoor and ICICI Bank Managing Director and CEO K V Kamath.

ICICI Bank executive director Chanda Kochhar in a statement said the ATM network sharing alliance reiterates the bank's commitment towards maximising customer convenience.

ICICI Bank has seen sharp usage of ATMs and other electronic channels in the recent past with 70 per cent transactions routed through these channels, the bank said.

ICICI Bank's ATM network was pegged at over 2,725, while that of HDFC Bank was in excess of 800.

The initiative by SBI with ICICI Bank and HDFC Bank comes in the wake of other public and private sector banks forming ATM sharing consortium.

Recently, Canara Bank, Central Bank of India, Indian Overseas Bank, UCO Bank and Union Bank of India launched their co-branded ATM network 'CashOnline.'

There was also a consortium of banks under CashTree, which includes Bank of India, Union Bank, Indian Bank and Syndicate Bank.