Faced with a Friday deadline, unions representing 3,800 full-time employes of the New York Daily News met today to discuss labor concessions to help save the ailing tabloid. Seven of the 11 unions have already agreed to staff reductions and other concessions, but the powerful drivers union is still at odds with News negotiators.

Both management and labor representatives expressed guarded optimism that the Friday deadline would be met, however.

The Daily News set the Aug. 6 deadline in mid-July when negotiations stalled with the four unions--the drivers, mailers, paperhandlers and pressmen. At that time, News President Robert M. Hunt offered to extend all labor agreements three years beyond the present 1984 expiration date. He further promised termination bonuses to employes whose contracts do not include job guarantees.

At the same time, Hunt sent letters to the homes of all employes warning of a "shrinking" News if there was no agreement with the unions. On Monday, with the four unions still holding out, Hunt announced cancellation of this Sunday's "bulldog," or first edition.

Hunt warned of additional cutbacks after Aug. 6 in another recent letter to employes.

Management and the drivers are at odds over the paper's proposal to replace the News' own deliverers in Nassau and Suffolk counties with contract deliverers. The other unions are unhappy over the number of their members the News wants to cut from the payroll. However, the three unions are expected to fall in line if the drivers reach agreement with the paper.

Overall, the newspaper wants to reduce the work force by 1,340 full-time employes. The News' parent, Chicago-based Tribune Co., has proposed a $92 million package that includes the cost of buy-outs or bonuses to reduce the work force and modernizing the tabloid's aging plant.

The Tribune Co. put the News on the sales block last December after the paper lost $12 million in 1981.