Myer chief executive Bernie Brookes has defended his move to lower the full-year profit guidance for the department store giant, saying the company would not make further spending cuts.

In an interview with Business Spectator, Brookes said the retail market is still difficult.

"We decided to take the guidance down rather than pull those two things out because we're conscious that we need to invest for the future," he said.

"We think we would do ourselves more damage by delaying omni-channel and by not investing in customer service."

Brookes said the introduction of GST did not match the current environment's problems.

"Each day when we get our text to look at the sales you just do not know what's going to happen," he said.

"It's a very, very unusual trading period where there's wild swings in people purchasing. Today's equity market has an impact on tomorrow's sales and this is a highly reactionary environment and one that makes it very difficult to drive forward."

This article first appeared on SmartCompany.