** Citi says Premier Investments' poor half-year trading update was due to higher-than-expected cost of doing business

** Brokerage cuts stock PT to A$30 from A$36, retains "neutral" rating

** Australian retailer said it expected global sales from its retail business, consisting of Peter Alexander and Smiggle brands, to be in the range of A$855 mln to A$865 mln ($526.25 mln to $532.41 mln) in 1H25 vs A$879.5 mln from the same period last year

** Stock logged worst session since late March 2020 on Monday

** The business has over the past few years been adept at managing cost inflation and so perhaps we have gotten too comfortable with that - Citi

** Brokerage expects Smiggle stationery brand to constitute most of retail business's underperformance, as Peter Alexander designer sleepwear brand is expected to be a major growth driver

** The continued pace of growth in Peter Alexander may not be a given - Citi

** Premier down ~13.5% so far this year, lagging behind a 0.4% rise on the benchmark ASX 200 index

($1 = 1.6247 Australian dollars)

(Reporting by Nikita Maria Jino in Bengaluru)

((Nikita.Jino@thomsonreuters.com;))