UltraTech Cement, backed by Indian billionaire Kumar Mangalam Birla, may buy a controlling stake in ARM Cement of Kenya, a Nairobi-based newspaper reported. ARM announced December 23 it’s in talks with an unidentified institutional investor about a $125 million investment. Chief Executive Officer Pradeep Paunrana declined to comment Tuesday when Bloomberg called him, citing regulatory compliance. Pragnya Ram, a spokeswoman for the Aditya Birla Group that controls UltraTech, didn’t immediately respond to an e-mail and a text message seeking comment.