Sonic Healthcare and Healthscope have pared back their proposed pathology deal, after the competition regulator raised expectations the deal might be rejected by delaying its decision last month.

Sonic Healthcare announced in May its intention to buy Healthscope's pathology businesses, which is private equity-owned, in Western Australia, Queensland, New South Wales and the Australian Capital Territory for $100 million. 

But the ACCC, in a statement of issues released last month, said it was its "preliminary view" the acquisition might raise competition concerns. 

Now, the two companies say Sonic will attempt to buy only the Western Australia and Queensland businesses, for a combined price of $47 million.The sale of the NSW and ACT businesses had been dropped "due to the time elapsed since the transaction was announced," Healthscope said in a statement.

The company has been contacted for further comment. Sonic added that it was unable to specify a likely completion date for the Queensland and WA purchase.

The statements follow a report last week that Healthscope was updating its lenders and analysts, just a couple of years after TPG and Carlyle bought the business for $2.7 billion. 

Shares in Sonic finished the day down 36 cents, or 2.7 per cent, at $12.88.