In one of its biggest acquisitions in recent years, Boston Scientific Corp. on Thursday announced plans to buy Coon Rapids-based Bayer Interventional for $415 million in cash.

For Massachusetts-based Boston Scientific, which has substantial operations in Minnesota, the purchase adds two new product categories that treat blood flow problems.

Bayer Interventional, a unit of German corporate giant Bayer AG, is a leader in technologies that clear clots from blood vessels, a process called thrombectomy.

Bayer Interventional, whose 350 Minnesota employees are not expected to lose their jobs in the takeover, also markets minimally invasive devices that use high-powered streams of water to remove plaque from clogged veins and arteries outside the heart.

"These are new spaces for us," Jeff Mirviss, president of Boston Scientific's peripheral interventional division, told the Star Tribune in an interview. "Breadth and scale matter."

With the expected completion of the purchase in the second half of 2014, Boston Scientific will control about 40 percent of the thrombectomy market. And it will be well-placed in the rapidly growing business of clearing clogged veins and arteries.

Mirviss said worldwide sales volume for all companies operating in both sectors is roughly $600 million. The purchase deal was several months in the making.

"We have a lot of respect for what Bayer Interventional has done," Mirviss explained. "We watched them grow their business."

In 2013, Bayer Interventional generated approximately $120 million in sales.

Boston Scientific, one of the nation's largest medical device companies, had revenue of more than $7 billion in 2013. But this acquisition is strategically significant. In a statement announcing the sale, Mir­viss said "the addition of Bayer Interventional will … enhance our ability to provide … a complete portfolio of solutions to treat challenging vascular conditions."

The company said it expects its expenditure on Bayer Interventional to dilute earnings per share "slightly" in 2014 and be "immaterial" in 2015.

Boston Scientific closed 10 cents a share lower Thursday, dropping to $12.69 per share.

The Bayer Interventional purchase adds to Boston Scientific's already significant presence in Minnesota. The company has facilities in Maple Grove, Plymouth and Arden Hills.

"We are glad to welcome employees of Bayer Interventional," Mirviss said. "People and talent are part of this deal."