A selection of events containing two charged leptons and significant missing
transverse momentum has been carried out using a total data sample of 
680~pb$^{-1}$ collected at $\rm e^+e^-$ centre of mass energies between 183
and 208 GeV. The observed number of events are consistent with the
expectation from Standard Model processes, which come mostly from 
$\rm W^+W^-$ production where both W particles decay leptonically. These
events have been used to carry out a search for the pair production
of sleptons, leptonically decaying charginos and charged Higgs particles.
No evidence for new phenomena is apparent and model independent
production cross section limits for the new particles are presented.