For the financial year ended March 31, 2012, the fair value of the BSE's unlisted shares stood at Rs 161.48 apiece.
The bourse's fair value, which is the the company's estimate of the minimum value of its shares based on earnings, reserves and book value for the year ended March 31, 2013, was at Rs 139.06 apiece.
"The exchange has determined the 'Fair Value' of shares of BSE Ltd, duly certified by the auditor of the exchange at Rs 139.06 per share," BSE said in a circular.
BSE said 'Fair Value' can be taken into account by the trading members for the purpose of computation of their networth as on March 31, 2013 and thereafter for the purpose of computation of networth as on September 30, 2013.
The bourse's net profit declined to Rs 108.57 crore for the year ended March 31, 2013 from Rs 178.13 crore in the preceding fiscal.
Also, BSE's total income fell to Rs 552.80 crore in the fiscal 2012-13, from Rs 578.42 crore in the previous financial year.
According to stock brokers, the change in BSE's fair value is mainly due to the fall in earnings.