San Clemente-based ICU Medical Inc.’s shares spiked today on a published report saying it’s attracted takeover interest from a rival.

ICU shares closed up 6% to a market value of $1.05 billion. The company makes infusion therapy devices.

San Diego-based medical device maker CareFusion Corp. is considering an offer for ICU, according to a Reuters report that cited unnamed sources and said that at least one “major private equity firm” has been doing due diligence and considering a bid.

Lake Forest, Ill-based Hospira Inc., ICU’s longtime primary customer, expressed interest earlier, according to Reuters.

ICU, Hospira and CareFusion all declined comment to Reuters.

Talk of a possible ICU sale first emerged a month ago after Bloomberg reported that the device maker engaged J.P. Morgan Chase & Co. to look at a deal that could fetch up to $1 billion for it.