Officials at Crown Castle International said the Securities and Exchange Commission has completed a probe into various accounting matters without taking any enforcement action. The cell phone tower operator said last summer that the regulator’s investigation included whether grants of stock options may have been backdated.

At the time, Crown Castle revealed that it had launched it own internal probe and found no instances of inappropriate actions relating to the administration of its equity-based compensation plans. However, company officials conceded that for certain stock option grants during the period of 1998 through 2001, the proper measurement date for accounting purposes differed from the measurement date used by Crown Castle. The company does not believe the discrepancy was material.

Last week, a group of investors noted that they were selling 36.4 million shares of the company’s stock at $35.83 apiece in a secondary offering. The investors include Fortress Investment Group, Greenhill Capital Partners, and Abrams Capital. Crown Castle said it will not receive any proceeds from the sale of the stock.