Adds revenue, background Sept 22 (Reuters) - IT services firm Accenture Plc ACN.N forecast first-quarter revenue below expectations on Thursday, weighed down by IT spending cuts amid high inflation and impact from a stronger dollar. Foreign exchange headwinds have intensified since Accenture's third-quarter results, with the U.S. dollar at a two-decade high against a basket of currencies and up about 16% so far this year amid sharp Fed rate hikes and rising geopolitical tensions. This has impacted companies with significant overseas operations including Microsoft MSFT.O, Salesforce CRM.N and IBM IBM.O.