Sept 9 (Reuters) - American Express Co (AXP.N) on Thursday again delayed a return to the office for its U.S. employees due to the fast-spreading Delta variant, setting Jan. 24 as the target date at the earliest. The variant has driven a rapid surge in COVID-19 cases around the globe, forcing businesses to reconsider their return plans and mandate vaccinations and masks for employees working from the office. American Express, which had earlier this year delayed its return to office plans until mid-October, said it was giving more flexible work options to its employees globally including virtual arrangements. The company expects most employees to be working in a hybrid scenario, based on a survey that showed it was preferred by a majority of its workers.