Under the arrangement, the Sri Lankan bank can draw up to USD 1.1 billion for a maximum period of six months.
This special arrangement is in addition to the existing Framework on Currency Swap Arrangement for the SAARC member countries.
In March, RBI had signed a Currency Swap Agreement with the Central Bank of Sri Lanka for USD 400 million under the existing SAARC Currency Swap Framework within the overall limit of USD 2 billion.
The proposal to extend the additional currency swap facility of USD 1.1 billion for a limited period was decided by the government in April based on the recommendation of RBI.
It was intended for mitigating the possible currency volatility in the spirit of strengthening India's bilateral relations and economic ties with Sri Lanka, RBI said.