Union leaders representing the lithographers and bookbinders employed at Harvard said yesterday they expect the strike against the University's printing office to last indefinitely.

One union official said he would not be surprised if the strike continues until the day before Commencement.

John B. Butler, Harvard's director of personnel, said yesterday he would not try to predict how long the strike will last. Butler did say, however, that there are still significant differences between the University and the striking workers.

The strike began last Tuesday after negotiations between the University and the workers failed to produce a settlement. No negotiating sessions have been held since the strike began.

Both Butler and union representatives said yesterday that they are ready to resume negotiations at any time.

James Norton, the union's bargaining agent, said yesterday he is willing to return to the table, but he does not think negotiations will bring a settlement right now because the differences between the two sides are so great.

Wages at Issue

Butler and union representatives agreed that the main issue in the strike is wages. The University has offered a 5.5 per cent increase in pay, while the workers have asked for increases of 10 to 14 per cent.

Paul Golden, vice president of the lithographers' union, said yesterday that lithographers employed by Harvard are paid about 20 per cent less than other unionized lithographers working in the Boston area. He also said that the pay hikes proposed by the workers themselves would still leave them at a lower wage level than their counterparts in other area shops.

Few Unions

Butler said yesterday that only a few lithographers in the area are unionized. He said the wages of Harvard lithographers must be compared to the wages of all lithographers, not just unionized personnel.

Butler said the wages of Harvard lithographers compare favorably with those of most lithographers in the area. Norton countered Butler's claim, saying it was misleading to compare the wages of Harvard lithographers with those of nonunion lithographers.

He said that the Harvard printing office is "a first-class operation," demanding high-quality work. Norton said that few non-lithographers in the Boston area are qualified to perform this work.

Fringe Benefits

The University also contends its contract offer to lithographers is fair for three reasons besides the wage offer made by its negotiator:

Harvard provides "superior" fringe benefits;

Harvard offers great stability in employment; and

Some employees in the printing office are the highest paid hourly employees in the University, with present rates of $6 per hour.