Two groups are planning to make bids for Gump’s.

A New York venture capitalist plans to enter the bidding against retail magnate Cyril Magnin’s sons for Gump’s, the specialty gift shop chain based in San Francisco that was put up for sale last month by Macmillan Inc. Lawrence R. Campbell said he expects to enter a bid on the pricey stores by the end of the week. Magnin said earlier that his sons, Jerry and Donald, also are interested in buying Gump’s. Campbell is heading a group of “five or six” investors. One of them is Jack Bass of the J. M. Bass & Co. private investment firm of Nashville, Tenn., he said. Citicorp of New York may also be involved in the financing.