Tennant is off to a strong start to fiscal-year 2018, with first-quarter revenue up 42.8 percent.

The Golden Valley-based manufacturer of industrial cleaning equipment on Monday posted first-quarter results stronger than analysts expected.

Net earnings for Tennant were $3.3 million, or 18 cents a share; in the same period of 2017, the company posted a loss of $4 million, 22 cents a share.

Revenue was $272.8 million, with 33.2 percent of the increase attributed to the company's recent acquisitions. Wall Street analysts had expected the company to report revenue of $251.9 million and earnings of 15 cents per share.

"We are very pleased with our strong start to the year and are well-positioned for additional momentum throughout the rest of 2018," said Chris Killingstad, Tennant Co. president and chief executive said in a statement.

Shares increased 6.7 percent in value on Monday to close at $74.45, moving them back into to positive territory for the year. The stock is now up 2.8 percent year-to-date.

Adjusted net earnings, which adjusted for acquisition and integration costs related to last April's deal for the Italian IPC Group were $5 million, or 27 cents per share.

"In the first quarter, we made important, ongoing progress against our growth and value-creation initiatives by improving field-service utilization and manufacturing efficiencies, introducing new products, developing strategic relationships to drive innovation, and executing on our sales strategy across all of our geographies," Killingstad said.

After the first quarter ended, Tennant announced plans to introduce an autonomous floor care machine later this year in the North American market as part of a relationship with Brain Corp., a San Diego-based artificial intelligence technology company that takes manually operated machines and turns them into autonomous robots.

Tennant also announced it is increasing financial guidance for the rest of the year.

The company increased the range for 2018 sales and earnings per share.

The company now says sales will be $10 million more at $1.08 billion to $1.11 billion. Adjusted EPS guidance rose 5 cents to a range of $1.85 to $2.05.

Killingstad told analysts the company's "vitality index" — sales of new products introduced within the last three years — was 44 percent in the quarter above the company's goal of 30 percent.

He said Tennant remains committed to a strategy that balances its ongoing investments to pursue organic growth and the ability to consider other opportunities should they present themselves.