(Adds Varian statement, Sirtex outlook, CEO comments)
May 22 (Reuters) - Varian Medical Systems said it would not increase its offer to buy Australian liver cancer treatment provider Sirtex Medical Ltd after Sirtex on Tuesday said Chinese private equity firm CDH Investments had submitted a formal bid.
CDH Investments this month made a last-minute offer of $1.4 billion, or A$33.60 per share, for Sirtex Medical, topping Varian Medical Systems' proposal days before the U.S. firm was set to seal a takeover deal.
Varian continues to believe that its offer is superior to the CDH bid, the company said in a statement.
In January, Varian offered to buy Sirtex Medical for A$28 per share.
Sirtex, in a separate statement, said it would make a recommendation on which proposal it believed was in the best interests of shareholders after assessing the CDH offer.
"Since the announcement of the Varian scheme, Sirtex has experienced uncertainty and distraction, and this has contributed to dose sales being below expectations," Sirtex Chief Executive Andrew McLean said.
The company's worldwide dose sales from January to April this year fell 10.6 percent, it said.
Sirtex's second-half dose sales are expected to be relatively flat versus the first half, McLean said.
Sirtex also said it now expects its fiscal 2018 underlying earnings before interest tax and amortization to come in at the lower end of previous guidance of A$75-A$85 million ($56.94 million-$64.53 million).
$1 = 1.3172 Australian dollars Reporting by Susan Mathew in Bengaluru; Editing by Clarence Fernandez and Sunil Nair