HARRISBURG — Ex-Pennsylvania Treasurer Rob McCord pleaded guilty Tuesday to two federal counts of attempted extortion, admitting that he tried to use his position to strong-arm state contractors into donating money to his failed gubernatorial campaign.

The plea followed a steep, fast fall from public office for the once-promising candidate for governor. During the hearing in a federal courtroom in Harrisburg, McCord acknowledged the plea agreement that prosecutors filed Feb. 2. He declined comment to reporters afterward.

U.S. District Judge John E. Jones III set a closed-door presentencing hearing for June 29, but did not set a sentencing date. The maximum penalty for each of the two charges is 20 years in prison and a $250,000 fine.

In court, McCord admitted trying to use his position as treasurer to threaten a Philadelphia-based law firm and a Western Pennsylvania-based property management firm into donating a satisfactory amount of money to his campaign last spring.

The investigation has fueled speculation in political circles about what led investigators to record McCord’s conversations, what took so long to charge him and whether he cooperated against anybody else in the political or finance communities. Those questions remained unanswered Tuesday, and federal investigators have declined to discuss the probe.

McCord, 55, a venture capitalist before he was elected treasurer in 2008, was serving his second term when he announced Jan. 29 that he would step down and return to the private sector.