Section 33. Election of certain optional retirement benefits by participating employers

By the adoption, filing  and  approval,  where
  required,of  a  resolution  in  the  manner  provided by section thirty,
  section  thirty-one  or  section   thirty-two   of   this   article,   a
  participating  employer  may  elect to provide for its own employees the
  benefit provided for persons in  the  employ  of  the  state  listed  in
  subdivision j of section forty-one and may elect to provide the benefits
  provided for employees of participating employers in section sixty-b and
  section  seventy-five-i  of  this  article.  Such  election may be for a
  limited period if such limitation is included in  the  resolution,  upon
  the expiration of which such election will be deemed revoked.