ACC Ltd and Ambuja Cements Ltd have placed their proposed merger on hold due to constraints related to the transfer of mines under current laws, reports the Hindustan Times. 

"The current regime on transfer of mineral concessions is still evolving and does not provide for a merger currently," said a spokesperson for ACC. "Given the challenges of achieving such transfers across 18-20 states, it was found prudent not to pursue the same at this point of time."

The merger has been under review since May 2017 and still "remains the ultimate objective", according to ACC.