Shares of Plexus Corp. /zigman2/quotes/208217351/composite PLXS -1.68% slid 2.1% in premarket trading Tuesday after the electronic manufacturing services company warned that it will miss fiscal first-quarter profit and revenue guidance provided in October because of "unanticipated" supply chain challenges that accelerated in the finals weeks of the quarter. The company cut its outlook for net earnings per share to 80 cents to 84 cents from $1.01 to $1.17, saying the new outlook includes about 6 cents a share of unexpected severance costs. The revenue outlook was cut to $815 million to $820 million from $825 million to $865 million. The current FactSet consensus for EPS is $1.09 and for revenue is $846 million. "While the demand environment remains robust, new and unexpected supplier delivery shortfalls in the Americas region resulted in a revenue, GAAP operating margin, GAAP EPS and free cash flow shortfall," said Chief Executive Todd Kelsey. "We anticipate these supply chain headwinds will persist in the near term." For the fiscal second quarter, the company expects sequential growth in revenue but "limited improvement" in EPS. The stock has edged up 0.6% over the past three months through Friday while the S&P 500 /zigman2/quotes/210599714/realtime SPX -0.58% has gained 3.9%.