Union and company representatives will meet May 21 to discuss when Lehigh Portland Cement Co. workers will vote on which union will represent them.

The two sides will meet with officials from the National Labor Relations Board in Baltimore, said James E. Harris, the unionrepresentative at the plant here.

Representatives from Lehigh's plant in York, Pa., which has 49 employees, also will be at the meeting, Harris said.

Five years ago,Lehigh workers became dissatisfied with the International Brotherhood of Boilermakers. They now want to join the United Paperworkers International, he said.

Because of an unfair labor practice suit filedby workers against Lehigh that had been pending since 1987, workers have been unable to leave the Boilermakers. The lawsuit was settled last year in the workers' favor.

The NLRB negotiated a $5 million settlement for employees, but workers have yet to receive their money,Harris said.

About 130 of the 160 employees here have signed cards saying they want a chance to vote for the Paperworkers, he said. Lehigh workers at plants in Cementon, N.Y., and Mitchell, Ind., also want to join the Paperworkers, Harris added.