UPDATE 1-Qiagen says 2015 results miss expectations

* 2015 sales rise estimated 3 pct at constant currency

* Qiagen had predicted growth of 4 pct

* EPS also misses view at $1.13-$1.14

* CEO says timing of some revenues was volatile (Adds comment from CEO on reasons for miss)

BERLIN, Jan 10 (Reuters) - German genetic testing specialist Qiagen has missed its own forecast for sales and profits last year, saying on Sunday it now estimates sales were up about 3 percent at constant currency exchange rates.

Qiagen, which had predicted sales would be up 4 percent at constant currency rates, said adjusted diluted earnings per share for 2015 were now estimated to have been $1.13-$1.14, down from its previous expectation of $1.16.

“This performance was hampered by factors that included volatility in the timing of revenues from the growing portfolio of companion diagnostic partnerships as well as lower revenues from instruments,” Chief Executive Peer M. Schatz said in a statement.

However, a strengthening of the dollar, Qiagen’s reporting currency, means that at actual rates, sales declined about 5 percent to some $1.2 billion, Qiagen said in a statement.

It said it expected adjusted net sales to rise about 6 percent at constant exchange rates in 2016, with adjusted diluted EPS to rise in line with that.

Qiagen will report final 2015 results on Feb. 2. (Reporting by Victoria Bryan; Editing by Greg Mahlich and Mark Trevelyan)