By Caroline Valetkevitch

NEW YORK (Reuters) - An aggressive Federal Reserve, soaring inflation and geopolitical uncertainty from the war in Ukraine are muddying the outlook for the upcoming U.S. earnings season, leaving some strategists wary of surprises as corporate results kick off this week.

Expectations for earnings growth have largely held up in recent weeks, despite a first quarter that saw commodities prices surge after Russia invaded Ukraine, threatening to exacerbate already-high consumer prices.

Analysts expect S&P 500 earnings to have increased by about 6% in the first three months of 2022 from a year ago and forecast profit growth of about 9% for the year, forecasts in line with those at the start of the month, according to IBES data from Refinitiv.

The reporting period for S&P 500 companies begins this week with results from major banks including JPMorgan Chase on Wednesday.

Some worry, however, that a cocktail of rising prices, higher wages and tightening financial conditions may have weighed on some companies' balance sheets or clouded expectations for the rest of the year.

"The environment is very different this quarter. There are so many things going on," said Jack Ablin, chief investment officer at Cresset Capital Management in Chicago. "It will be fascinating to see how companies respond."

Earnings season comes on the heels of a tumultuous quarter for asset prices that saw the S&P 500 swoon nearly 13% before paring losses in a furious rebound late last month. The index is down about 6% for the year-to-date.

Energy and other commodity prices have surged, with Brent crude futures up 32% for the year so far. The war in Ukraine has also created worries about supply and transportation problems, adding to concerns that have been building since the start of the coronavirus pandemic.

That's led a number of companies to warn about the impact of rising raw material and other costs on margins in recent weeks, including packaged food company Conagra Brands Inc, which this month lowered its full-year profit forecast.

"I see capital more expensive, labor more expensive, commodities more expensive," Ablin said. "Unless these firms can pass these costs along - and arguably they'll be able to pass along some but not all... That says to me, margins have to decline."

Tightening labor market conditions are boosting wages, another negative for companies. The Conference Board's consumer confidence index rebounded in March amid growing labor market optimism.

In March, the Fed raised rates for the first time since 2018 and policymakers have signaled they are ready to aggressively fight the fastest consumer price growth in nearly four decades with meaty rate hikes and balance sheet runoff, leading some investors to worry that the central bank's monetary policies may bring on a recession.