Super Retail Group’s profits have fallen short of market expectations, with heavy discounting across its chains squeezing margins just months after the company sacked its chief executive over a relationship scandal.

The owner of Supercheap Auto, Rebel, BCF and Macpac on Monday forecast normalised profit before tax of between $172 million and $175 million for the six months to December 27, down from $184.4 million a year earlier.

That came despite first-half revenue rising 4.2% to about $2.2 billion.

The retailer blamed “elevated promotional activity” across the sector for the weaker profit outcome, saying increased discounting – particularly at Rebel – had weighed on gross margins.

High levels of store network activity also added costs, with seven stores opened, six closed and three refurbished or relocated during the half.

Investors reacted swiftly, sending Super Retail shares down about 6% to around $14.80.

New managing director and chief executive Paul Bradshaw (pictured below) said the group delivered “another record first-half sales result”, but acknowledged margins had come under pressure.

“The group traded well, albeit with an elevated level of promotional intensity impacting realised gross margins, most notably in Rebel,” Bradshaw said.

By brand, Supercheap Auto remained the biggest earner, posting $813 million in revenue and between $101 million and $102 million in profit before tax.

Rebel recorded $741 million in revenue and $53 million in profit, while BCF delivered only modest sales growth of 0.3%, hurt by weather and environmental factors in Victoria and South Australia.

Macpac was the standout on sales, with revenue up 13.1%, though its margins were also impacted by clearance activity.

Like-for-like sales across the group rose 2.5%, led by Macpac, while BCF went backwards.

Bradshaw took the top job last year after former CEO Anthony Heraghty was sacked for misrepresenting his relationship with the company’s former head of human resources to the board. Super Retail will release its fully audited half-year results on February 26.