  The cross sections for the pp -> ppK+K- reaction were measured at three beam
energies 2.65, 2.70, and 2.83 GeV at the COSY-ANKE facility. The shape of the
K+K- spectrum at low invariant masses largely reflects the importance of
K\bar{K} final state interactions. It is shown that these data can be
understood in terms of an elastic K+K- rescattering plus a contribution coming
from the production of a K0\bar{K}0 pair followed by a charge-exchange
rescattering. Though the data are not yet sufficient to establish the size of
the cusp at the K0\bar{K}0 threshold, the low mass behaviour suggests that
isospin-zero production is dominant.
