Monumental Motor Tours Inc., which has been running bus tours for the past 67 years, has suspended service because of declining ridership and mounting operating expenses.

"The owning and operating of coaches has become too expensive," said Kenneth R. Schwarz, president of the Baltimore company.

Monumental stopped running its 17 buses Jan. 6 and dismissed 35 employees, leaving six on the payroll, said Mr. Schwarz, whose family has owned the company since its founding in 1925.

Most of the people who lost their jobs were drivers, he said, but some mechanics and clerical workers were included in the layoffs.

The company will continue to operate, but "we haven't really decided what we are going to do," Mr. Schwarz said.