Oct 26 (Reuters) -

* India's capital markets regulator SEBI issues review of block deal window mechanism

* India regulator SEBI says will implement two block deal windows, one in morning, one in afternoon

* India regulator SEBI says minimum order size for execution of trades in block deal window must be 100 million rupees

* India regulator SEBI says new block deal window rules to come into effect on Jan. 1, 2018 Source text for Eikon: (http://bit.ly/2lfxgqZ) (Reporting by Rafael Nam)