Nautilus Inc. bought Brooklyn Park-based Octane Fitness for about $115 million, the companies said Monday.

Octane, founded in 2001 by Dennis Lee and Tim Porth, initially made elliptical machines but now makes a wide array of equipment sold through specialty and commercial channels.

Nautilus, a publicly traded company based in Vancouver, Wash., makes fitness equipment under brand names such as Nautilus, Bowflex, TreadClimber, Schwinn and Universal and sells its products primarily through direct-to-consumer and through retail locations.

Lee said Nautilus is a good match in terms of products and distribution.

"They are fantastic at consumer direct and they are great at sporting goods and mass merchant retail," he said. "Our core competencies are the fitness specialty retail business, the commercial business and the international businesses."

Nautilus is acquiring the company from North Castle Partners, a private equity group based in Greenwich, Conn., that has been a primary investor for about 10 years, and other investors.

"We feel very blessed to have had a great partnership with North Castle in the 10 years we worked together," Lee said.

Octane and its approximately 80 employees are staying in Brooklyn Park. Lee and co-founder Porth will join the Nautilus management team.

In the Nautilus conference call announcing the deal, company officials said they had been looking for an acquisition for a year and had looked at more than 100 targets.

One of the company's key criteria in the deal was finding a good cultural matchup.

"These guys think and operate just like us," officials said.

Nautilus will report its fourth-quarter and year-end numbers on Jan. 19; in 2014, it reported revenue of $274.4 million and net income of $18.8 million.

In the news release announcing the deal, Nautilus said it expects Octane to record about $65 million in annual sales for 2015 and to begin adding to Nautilus earnings during the current quarter.

Nautilus shares closed at $18.48, up $1.76, or 10.5 percent, on the day.