Galfar Engineering and Contracting announced an 86% drop in profits for 2014 to $2.6m (2013: $17.9m), according to a statement filed with the Muscat Securities Market.
The contractor, which was hit by a bribery scandal which saw founder and managing director P Mohamed Ali handed a 15-year jail sentence in January 2014, said revenues had fallen by 10% to $920m (2013: $1.02bn).
Ali was convicted on five separate counts of offering bribes in exchange for contracts to a finance ministry official who also served as head of procurement for state-owned oil company Petroleum Development Oman.
He was given a three-year term for each of the counts, which are to run consecutively. He was also ordered to pay $4.61m in fines.
He has maintained that he is innocent of the charges and has previously said he intends to appeal against them.