* Q2 sales fall 5 pct to 3.226 bln
* Q2 operating profit down 16 pct on IPO, severance costs
* Reaffirms full-year guidance (Recasts, add details)
BERLIN, May 3 (Reuters) - Siemens Healthineers on Thursday posted a 16 percent decline in operating profit in its fiscal second quarter, hurt by restructuring costs and expenses associated with its recent stock market listing.
The medical imaging and diagnostics company, which was spun off from its parent Siemens in mid-March, said its operating profit came to 457 million euros ($547 million) in the three months thorugh March, hit by 103 million in severance charges and costs for the initial public offering (IPO).
Analysts had on average forecast operating profit of 430 million euros, according to a poll published by the company.
Quarterly sales dropped 5 percent to 3.23 billion euros, shy of consensus for 3.25 billion euro.
Strong sales at its core medical imaging business, which grew 6 percent on a comparative basis, helped offset a sluggish quarter in its diagnostics unit where revenue was flat.
Healthineers is pinning its hopes on Atellica Solution, its new flagship blood and urine diagnostics machine, to turn around its underperforming In-Vitro diagnostics business where it lags market leader Roche.
It hopes to place 7,000 new machines by 2020 - around a third of its current installed based of 21,000 - and said it remained on track to place up to 1,000 machines by the end of its fiscal year.
The maker of medical gear such as X-ray and MRI machines reaffirmed its guidance for an adjusted operating profit margin of 17 to 18 percent for 2018 and comparable revenue growth of 3 to 4 percent. ($1 = 0.8348 euros) (Reporting by Caroline Copley Editing by Edward Taylor and Maria Sheahan)