The National Labor Relations Board has ruled that about 45 supervisory employes of The Washington Post must be excluded from union representation by The Newspaper Guild, but that at least 111 other employes whom The Post's management sought to exclude should continue to be eligible for Guild membership.

The NLRB decision, reached Jan. 14 and announced yesterday, ended a five-year dispute between The Washington Post Co. and Washington Local 35 of the Guild, an AFL-CIO affiliate that claims union jurisdiction over about 1,100 employes in the newspaper's news, editorial and commercial departments. More than 600 employes currently hold Guild membership.

The dispute began when the company in 1976 asked the NLRB for what is called a "clarification" of which jobs should be represented by the Guild. It contended that 156 mostly middle-level editors and managers should be considered "supervisory" employes and thus exempt from union membership under terms of the Guild-Post contract.

Guild officials contested the company's move, contending it would weaken the Guild's bargaining position on wages and hours and would eliminate union security for the affected employes.

During hearings before hearing officer Albert W. Palewicz that lasted 91 days and filled 10,650 pages of transcripts, the duties of all 156 contested jobs were reviewed.

In its 185-page decision, the full NLRB decided to exempt by job titles an apparent 45 principal commercial managers and supervisory editors with substantial administrative duties from Guild Jurisdiction, while maintaining the right of some 111 others to be represented by the union. The current Guild-Post contract adopted in 1979 does not require anyone to belong.

Alan D. Eisenberg, attorney for the Guild, said he lamented losing any members "but I think the Guild came out very well in this decision. . . . On the whole, we are well satisfied." Dorothy A. Struzinski, administrative officer of the Guild, said the NLRB decision was "good word."

Lawrence A. Wallace, the Post's vice president for labor relations, said he had not yet read the NLRB decision and declined comment.