Sept 18 (Reuters) - Shares of BlueScope Steel Ltd slipped to an over three-month low as the ongoing United Auto Workers (UAW) strike against the Detroit Three automakers in the United States weighs on the Australian steel-maker's North American business.

BlueScope Steel shares fell as much as 3.8% to A$18.870, their lowest since June 2, and are on track to log a sixth straight session of losses.

The company generated nearly 42% of its fiscal 2023 sales revenue of A$18.17 billion ($11.71 billion) from North America, with its low-cost, hot rolled coil regional supplying business - North Star - bringing in A$3.38 billion.

The UAW's strike against General Motors, Ford and Stellantis entered its third day on Sunday, with no immediate resolution on the horizon.

But the looming possibility of the strike had pushed U.S. hot-rolled coil (HRC) prices down 3.4% from end-August to $704 per tonne on Sept. 15, the day the strike started.

"While the Australian domestic market is holding up, North Star profits will be under pressure at these lower spot levels," analysts at Citi said in a research note.

The analysts said North Star's HRC spread has contracted to $345 per tonne, which could impact the brokerage's earnings estimates.

Brokerage Jefferies said in a note that while North Star can move its products elsewhere, it cannot avoid the fall in spreads.

"With the auto sector representing 50% of North Star's end market demand, each week would theoretically impact BSL Group EBIT by A$7 million if all the auto tonnes were to go to zero, something we do not see as realistic," Jefferies analysts said.

"Rather, it is the fall in HRC spot spreads that impacts all North Star despatches."

Jefferies maintained its "buy" rating on BlueScope with a price target of A$24.00, while Citi retained its "neutral" rating with an A$23.50 target price. ($1 = 1.5516 Australian dollars) (Reporting by Sameer Manekar in Bengaluru; Editing by Savio D'Souza)