Senate President Pro Tem Brent Hill also named a six-person ethics committee to investigate Pearce's conduct. The committee will meet at 8 a.m.
Pearce maintains that he's committed no wrongdoing.
The ethics panel's members are Republican Sens. Dean Mortimer, of Idaho Falls, who will chair the committee, along with Bert Brackett of Rogerson and Jim Hammond of Coeur d'Alene.
Democratic members will be Sens. Elliot Werk of Boise, Diane Bilyeu of Pocatello, and Dan Schmidt of Moscow.
Democrats complained Pearce broke Senate rules by not adequately disclosing that oil and gas exploration companies have leased his property in Payette County during more than a dozen hearings and floor sessions in which measures affecting the industry were considered.
Hill told The Associated Press that accusations of wrongdoing alone don't merit the ouster of a Senate chairman.
"Any decision regarding his chairmanship will not be made based on mere allegations," Hill said.
He added that Pearce could only be prevented on voting on future oil and gas-related measures another of the Democrats' demands by a two-thirds vote of the Senate's members.
Hill urged the committee to conduct its work quickly.
If it determines no violation has occurred, the complaint will be dismissed.
If the committee determines probable cause of a violation exists, Pearce could ask for a formal hearing.
In that event, the committee could eventually recommend dismissal of the charges, reprimand, censure, or expulsion.
The last Senate ethics investigation in 2005, into whether former Sen. Jack Noble introduced legislation meant to enrich himself, resulted in Noble's resignation.
Hill was the chairman of that panel.
Senate Minority Caucus Chairwoman Michelle Stennett, D-Ketchum, didn't immediately return a phone call Friday seeking comment on Hill's decision to leave Pearce's committee chairmanship intact.
Pearce oversaw Friday's Resources Committee, including votes on a bid to limit the Idaho Land Board's acquisitions and a measure that would have exempted military veterans from taking hunter safety courses in order to get a hunting license.
Both measures failed.
The panel didn't consider any oil and gas legislation.
In their complaint lodged Thursday evening, minority-party members complained Pearce should have disclosed that he's leased his land to gas exploration companies during hearings and floor debate on several industry-related bills.
But Pearce maintains his disclosure, made Wednesday on a bill to limit local-government control of industry, was sufficient.
In an interview Thursday, the five-term lawmaker from western Idaho said he's done nothing wrong and contends that he will be cleared of any wrongdoing by the ethics investigation.
Pearce couldn't be reached for comment late Friday.