"Of course, I am upset but this is part of life," he told reporters here when asked for his reaction on the court order.
"I have always said I am open for legal scrutiny...I am sure the truth will prevail and I will get a chance to put forward my case with all the facts," Singh said.
He said he respected the judicial process in the country and "I hope in a fair trial I will prove my innocence."
Asked whether he would contest the case, he said he would discuss the issue with his legal team.
Earlier in the day, a special court here summoned Singh along with industrialist Kumar Mangalam Birla, ex-coal secretary P C Parakh and three others as accused in a case pertaining to allocation of Talabira-II coal block in Odisha in 2005 and asked them to appear before it on April 8.