Siemens Energy in May unveiled plans to buy the remaining third in Siemens Gamesa it does not already own for 4.05 billion euros ($3.99 billion), a plan that needs to be approved by Spanish regulator CNMV.
Under a tentative timeline Siemens Energy previously said that the bid would launch in mid-September.
"We cannot comment on the timing of the Spanish regulator CNMV, Siemens Energy has no influence on this. We would of course like to have a positive response as soon as possible, as we want to realize our objectives as quickly as possible," the company said in emailed comments.
"However, if our offer is examined with due diligence, this will be in the interest of all shareholders and thus also in our interest. In any case, the exchange with CNMV is constructive and professional."
($1 = 1.0149 euros)
(Reporting by Christoph Steitz, editing by Rachel More and David Evans)