March 18 (Reuters) - Occupational health services

provider Concentra Group, a unit of healthcare company Select

Medical Holdings ( SEM ), said on Monday it has confidentially

filed for an initial public offering (IPO) in the United States.

The number of shares to be offered and the price range for

the proposed offering have not yet been determined, Concentra

said.

Earlier this year, Select Medical ( SEM ) had announced its plan to

pursue the separation of Concentra, aiming to create two

independent, publicly traded companies. The process is expected

to be completed in late 2024.

The potential offering would add to the growing number of

healthcare firms looking to list amid a stuttering rebound in

the IPO market in the United States.

Healthcare provider PACS Group last week filed its paperwork

to go public in the U.S., while Peruvian firm Auna is set to

list on the New York Stock Exchange this week.

Private equity firm KKR-backed BrightSpring Health Services

also went public in January.

Founded in 1979, Concentra provides occupational medicine,

urgent care, physical therapy, drug screening and physical exams

in the United States.

The company operates 544 occupational health centers and 150

onsite clinics at employer worksites throughout 42 states, apart

from providing telemedicine for work-related illnesses and

injuries.

Concentra was previously owned by health insurer Humana

, which sold it in 2015 for about $1.06 billion to a

joint venture between Select Medical ( SEM ) and private equity firm

Welsh, Carson, Anderson & Stowe.

Select Medical ( SEM ) boosted its ownership in Concentra to 100% in

2021.