3M Co.'s $6.7 billion purchase of wound-care company Acelity Inc. will be the biggest acquisition in its history.

The Maplewood-based 3M, which makes everything from Post-it notes to safety equipment and optical films, said Thursday it is buying San Antonio-based Acelity and its KCI subsidiaries from investment funds Apax Partners, Canada Pension Plan Investment Board and the Public Sector Pension Investment Board.

The deal includes the assumption of $2.4 billion of Acelity debt.

"Acelity is a recognized leading provider of advanced wound-care technologies and solutions and an excellent complement to our health care business," said 3M CEO Mike Roman during a conference call with Wall Street analysts early Thursday. "With more than 3,000 patents, they are known for their innovation and ability to identify and address unmet clinical needs."

The move bolsters 3M's growth strategy, he said. Acelity has more than 4,500 employees worldwide and 2018 revenue of $1.5 billion.

The business is expected to help 3M accelerate its wound-care offerings and address increased needs in diabetic, obese and aging patients, Roman said.

Acelity's best-known KCI subsidiary markets a range of medical-care products in 90 countries.

It specializes in negative-pressure therapies that use vacuums to drain and clean wounds. It also sells surgical-incision management systems and advanced wound dressings. Last month, KCI filed preliminary documents with the Securities and Exchange Commission for an initial public offering. The IPO documents, however, were not fully completed.

In a statement, Acelity CEO Andrew Eckert celebrated the sale to 3M.

"Today, KCI embarks upon a new era in its long history as a pioneer in health care," Eckert said. "The combination of KCI with 3M will accelerate the reach of a business that is a leader in innovation, customer experience and clinical and economic evidence. Backed by the resources and expertise of 3M, KCI will be able to offer clinicians and patients even more compelling solutions designed to speed healing and improve outcomes."

If the Acelity deal gets regulatory approval and closes later this year as planned, it will join 3M's $6 billion health care business, company officials said.

Some analysts noted that the Acelity deal initially appears to be expensive. Its $6.7 billion price tag exceeds the $6 billion that 3M's entire health care business generated in 2018.

Still, Edward Jones research analyst Matt Arnold said in a note to investors that the firm sees "strong strategic rationale" for the acquisition.

"The purchase price is at the high end of what we would expect 3M to pay for a deal, but we think it is justified by the attractive growth profile and profitability of the business being acquired," he said.

While the deal would be 3M's largest acquisition, Arnold said it is still only 6% of the company's total market value "and should be a manageable integration into its existing portfolio of adjacent wound-care products."

Other analysts, such as CFRA research analyst Jim Corridore said he's not so sure the deal will quickly help 3M. "While we see synergies and a fit with MMM's medical solutions business, we think it will take time for the deal to pay back its steep cost," he said.

3M expects the acquisition to affect annual earnings by 35 cents a share, including finance costs. Excluding the one-time expenses, the company expects Acelity to add 25 cents a share to earnings.

The purchase also will affect 3M's share-repurchase plan, which will now be in the $1 billion to $1.5 billion range, instead of the previously set $2 billion to $4 billion.

3M's stock price fell nearly 1% to close Thursday at $184.75.

The acquisition comes one week after 3M delivered disappointing first-quarter results and newly announced plans to slash 2,000 jobs around the world.

Still, the deal delivers on promises Roman made to Wall Street investors in November. At that time, Roman, who took over as CEO in June 2018, announced a five-year growth strategy that he said would include acquisitions and focus on high-margin auto, safety and health care products.

3M's largest acquisitions to date are its $2.5 billion purchase of Capital Safety in 2015 and the $2 billion purchase of Scott Safety in 2017. Overall, 3M spent $9 billion buying 13 companies during the last five and a half years.

Former 3M CEO Inge Thulin said a few years ago that 3M would focus on doing "fewer but larger" deals that could help 3M drive growth during — what was then — a period of slow industrial growth.

Moody's analyst David Berge said in an e-mail that the deal has significant growth potential. But he acknowledged that it also "could have a negative impact on 3M's credit profile in that it will involve a substantial increase in debt over a very short period." Berge added that the deal could also affect the health care unit's operating margins and introduce integration risks.

"However, given Acelity's technological and market position, we recognize that the acquisition fits well into one of 3M's key strategic growth objectives, which is wound care," Berge said. "And [we] expect that 3M will leverage its global network and product know-how to further grow this franchise."

In buying Acelity, 3M will gain a holding company cobbled together over the years by the London-based private-equity group APAX Partners.

APAX created Acelity around 2014 after merging together several acquisitions that included Texas-based KCI, England based Systagenix and the New Jersey-based LifeCell.

LifeCell was sold in 2017.