Siemens AG saw the shares of its imaging and diagnostics unit soar in early trade from the placement price of €28 per share. The stock market debut was marred by an outage in the Eurex T7 trading system on the Frankfurt Stock Exchange. The starting level for Siemens Healthineers AG compares to the range set between €26 and €31 per share and values the stake at €4.2 billion if the overallotment or greenshoe options are included. The figure translates to €32 billion for the overall business.

The German industrial giant sold 13%, with the possibility to include another 2% in the initial public offering. The deal is the biggest in the country since RWE's Innogy raised €4.9 billion two years ago.

The medical technology company with the ticker SHL placed 150 million existing ordinary registered shares in the basic round. It traded 5.3% higher at €29.485 per share at 10:25 am, after the first transaction at €29.1 per share, a difference of 1.32%. Siemens was 0.85% in the green at €107.1 per share.