Fine tune the querry

Hello All,

im trying to loop throught the table and look for duplicate records and delete the duplicate records using the below query

For Mcur In ( select Max(empiid) empiid ,MAx(ROWID) MaxROWID from emp
       group by  empiid having count(*)>1)
   Loop
         Delete from emp where empiid=Mcur.empiid and RowId<Mcur.MaxROWID;
   End Loop;

Its taking more then 5hrs to complete, can i request your help on fine tunning the query so that it deletes the records within few minitues,

Thanks

sankar