By Giulia Petroni

Siemens Energy AG will be included in Germany's benchmark DAX stock-market index for one day on Sept. 28, when it is set to be spun off from parent company Siemens AG, according to global index provider STOXX Ltd.

Siemens Energy will enter the index with a price of zero, according to the index provider, and the number of shares and free float will be determined by the value of Siemens shares and the ratio for the spin-off.

"This adjustment ensures the trackability of the index for investors," STOXX said, adding the DAX will be calculated on a basis of 31 companies for one day.

On Sept. 28 at closing, Siemens Energy will be taken out of the DAX.

STOXX added that the next index review is scheduled for Dec. 3. 



  Write to Giulia Petroni at giulia.petroni@wsj.com