President-elect Jimmy Carter's inaugural committee, adopting a conservative approach to spending, asked a group of business and labor leaders yesterday to donate more money to pay for the public events designed to make this a "people's inauguration."

The committee so far has received only $70,828 in contributions of the $350,000 necessary to pay for the five days of free concerts, activities, and transportation for the general public scheduled during inaugural week, Jan. 18 to 22.

Committee cochairperson Bardyl Tirana met yesterday with about 230 business, labor and trade association leaders at a breakfast also attended by Carter's son Chip and his budget-director designate Bert Lance. Everyone paid $10 for their breakfast and heard Tirana make a direct plea for funds, he said.

The traditional inaugural events - the vice presidential receptions, parade, inaugural eve concert and inauguration night parties - are budgeted at $3 million. In keeping with customary practice, the sale of tickets to the events, license plates, commemorative medals, souvenir books and royalties from the television rights to the concert are supposed to pay for the events.

The public events, Tirana hopes, will be financed completely from contributions, on which the committee has imposed a $5,000 limit per organization.

Tirana also said yesterday that he has asked the Smithsonian Institution not to bell the committee for the $41,500 it will cost to keep its six museums and three art galleries open late for the public during inaugural week. Originally the committee said it would pay the money. The Smithsonian has not responded to Tirana's request yet, he said.

"We expect to be in the black when the final results are in," he said "but we won't know how much money we've made until after the inaugural. We don't want to spend money we don't have.I fully expect to be able to give the Smithsonian its $41,500; we're just trying to protect ourselves.

Essentially the plea for funds and free services results from the committee's reluctance to commit money on the basis of projections, Tirana said.

Regardless of money problems, Tirana said, the schedule of public events will go on. "It can't be canceled," he said, "It won't be canceled."

Tirana said the plea for donatins came only six days before the start of the public events schedule because he has not had time to work on fund raising previously.