GSK was seen as the front runner to buy the assets, whichinclude Advil painkillers and Centrum vitamins, after main rivalReckitt Benckiser quit the race on Thursday.
"While we will continue to review opportunities that mayaccelerate our strategy, they must meet our criteria for returnsand not compromise our priorities for capital allocation," ChiefExecutive Emma Walmsley said in a brief statement.
GSK shares jumped 4 percent to 13.23 pounds at 0809 GMT.
A Pfizer representative was not immediately available tocomment.(Reporting by Paul Sandle and Martinne GellerEditing by David Goodman)