The 1980 patronage rebate rate for Harvard Cooperative Society (Coop) members is 9.5 per cent, the largest percentage in recent years, the Coop announced yesterday.

The 0.7 percentage point jump over last year's rare of 8.8 per cent represents an eight-per-cent increase in the rebate rate.

The Coop's expansion in the last year accounts for much of the large rebate, James A. Argeros, general manager of the Coop said. The Coop recently opended a new women's shop next to the Annex and a new branch on Federal St., Argeros added. The Coop has also expanded its luggage, sporting goods, electronic goods, and young men's departments. "We're the Macy's of collegiate bookstores," Argeros said.

The Coop currently has no plans for additional physical expansion. "Our program is to upgrade and refurbish our existing facilities when necessary," Argeros said.

The Coop will instead concentrate on expanding its membership currently at an all-time high of 87,000. "Our goal is to have 100,000 members by our hundredth anniversary in 1982," Argeros said, adding that he expects this year's large rebate will attract new membership.

In addition to expansion and a large membership, Argeros attributes the high rebate rate to an increased efficiency. The Coop recently brought its credit operations into its main building. Formerly, the Coop leased office space for these operations.

The Coop will begin distributing rebates Wednesday, October 15