By Supantha Mukherjee STOCKHOLM (Reuters) -Ericsson said on Thursday that the U.S. securities regulator has opened an investigation concerning the matters described in the company’s 2019 Iraq investigation report. The Swedish telecom equipment maker said it was fully cooperating with the United States Securities and Exchange Commission (SEC) and it was too early to determine or predict the outcome of the investigation. Ericsson disclosed in February that an internal investigation had found it may have made payments to the Islamic State militant group in Iraq – misconduct it said “started at le…