The invention relates to a conversion process of a feedstock, preferably an oxygenated
feedstock, into one or more olefin(s), preferably ethylene and/or propylene, in
the presence of a molecular sieve catalyst composition that includes a molecular
sieve and a Group 3 metal oxide and/or an oxide of a Lanthanide or Actinide series
element. The invention is also directed to methods of making and formulating the
molecular sieve catalyst composition useful in a conversion process of a feedstock
into one or more olefin(s).