(Adds requirement to improve financial reporting)
MEXICO CITY, March 28 (Reuters) - Mexico has fined the embattled Mexican unit of Spanish construction firm OHL 71.7 million pesos ($4.1 million) over inadequacies in its financial reporting, though there was no evidence of fraud, the company said on Monday.
OHL Mexico has been battered by corruption allegations since recordings were leaked in the first half of last year, in which its executives appeared to be discussing overcharging the government for a highway concession.
The company will be required by the Mexican securities regulator (CNBV) to work with its external advisors to come up with an acceptable way to report its so-called "guaranteed return," OHL Mexico said in a statement to the stock exchange.
OHL Mexico, whose shares jumped nearly 7 percent in early trading, said in the statement it would hold a telephone conference at 2:00 p.m. local time.
$1 = 17.5085 Mexican pesos Reporting by Alexandra Alper and Veronica Gomez; Editing by Bernadette Baum