Updates to before market open

By Ragini Mathur and Avinash P

July 21 (Reuters) - Wall Street's main indexes were on track to open higher on Tuesday as semiconductor shares extended a recovery from a recent selloff, while investors awaited major tech earnings for clues on the future of the AI trade.

Markets also weighed mixed signals from the U.S.-Iran conflict after a senior Iranian official told Reuters on Monday that Tehran had received a proposal from mediators for a 10-day ceasefire.

Yemen's Iran-aligned Houthis said on Monday they ​would impose a naval blockade on Saudi Arabia, opening a potential new front against the U.S. in its war with Iran and raising the threat to global energy supplies and trade beyond the Gulf.

Brent crude futures returned to around $90 a barrel after earlier losses. O/R

Recently battered semiconductor stocks were leading premarket gains. The iShares Semiconductor ETF SOXX.O climbed 4.1%, rising for the second consecutive day.

"Investors have to juxtapose strong earnings against the ongoing war with Iran," said Art Hogan, chief market strategist at B. Riley Wealth.

"To end this tug-of-war, we need to hear from hyperscalers like Alphabet reaffirming their CapEx spending plans. Such affirmation from large players is likely to put a floor under the drawdown in semiconductor names."

Lately, chip stocks have come under heavy pressure, as investors question whether this year's powerful rally in the sector has gone too far and scrutinize the lack of tangible returns on hefty investments by hyperscalers.

The Philadelphia SE Semiconductor Index .SOX ended Friday more than 20% below its late-June record high, confirming a bear-market decline, though the index remains up about 66% for the year.

At 08:38 a.m. ET, Dow E-minis YMcv1 were up 96 points, or 0.18%, and S&P 500 E-minis EScv1 were up 26.5 points, or 0.35%. Nasdaq 100 E-minis NQcv1 were up 348.75 points, or 1.21%.

Recent volatility in chip stocks, which has spread to broader markets, pushed Wall Street's main indexes to three straight sessions of losses despite an upbeat start to the second-quarter earnings season and last week's cooler inflation print.

Investor focus this week will turn to results from Alphabet GOOGL.O and Intel INTC.O, which could help determine whether the AI trade has further room to run amid elevated profit expectations.

Adding to the uncertainty, President Donald Trump on Monday unveiled 50% tariffs on a wide range of imports from Canada. The U.S. administration said the move was in response to Canada's treatment of American-made cars, alcohol and dairy goods.

The Financial Times reported that Trump is expected to impose fresh tariffs on dozens of countries as soon as this week, with his 10% global tariff poised to expire on Friday.

Among early movers, 3M MMM.N shares gained 6.3% after the industrial giant lifted its full-year profit forecast.

Halliburton HAL.N dropped 3.7% even after the oilfield services company edged past Wall Street estimates for second-quarter profit.

Software stocks were also under pressure after Morgan Stanley cut ratings and price targets on some names.

Adobe ADBE.O, Intuit INTU.O, Workday WDAY.O and Salesforce CRM.N fell more than 4% each.