Royal Philips NV agreed to buy Volcano Corp. for $1 billion to expand in catheter-based imaging of the heart and blood vessels as part of a wider refocus on more profitable markets such as medical gear.

Shareholders of Volcano, whose equipment enables minimally invasive diagnostics and treatment of coronary artery disease, will receive $18 a share in cash, Philips said in a statement. Stock of the San Diego-based company closed at $11.49 yesterday.

The takeover comes almost three months after Philips Chief Executive Officer Frans van Houten’s announcement that the 123-year-old Dutch company will be split into two, separating the lighting unit as he focuses on health-care equipment and consumer goods. Volcano’s 2013 sales amounted to about $400 million, Philips said, adding the transaction will probably be completed in the first quarter of 2015.

“The agreement to acquire Volcano significantly advances our strategy to become the leading systems integrator in image-guided therapies,” said Van Houten.

The transaction, valued at a total $1.2 billion including cash and debt, is expected to be accretive to Philips’ reported earnings per share by 2017, and the Amsterdam-based company is targeting a margin on earnings before interest, taxes and amortization of about 20 percent for its image-guided therapy business by that year.