Oct 22 (Reuters) - American Express Co (AXP.N) reported a higher profit that topped Wall Street estimates for the fourth straight quarter, as higher usage of its cards, particularly by millennial and Gen Z customers, fueled a strong recovery in overall spending. After months of stagnation, credit-card issuers like AmEx are starting to see a turnaround in spending with resumption of social activities made possible by a rise in the number of fully vaccinated people. Oct 22 (Reuters) - American Express Co (AXP.N) reported a higher profit that topped Wall Street estimates for the fourth straight quarter, as higher usage of its cards, particularly by millennial and Gen Z customers, fueled a strong recovery in overall spending. After months of stagnation, credit-card issuers like AmEx are starting to see a turnaround in spending with resumption of social activities made possible by a rise in the number of fully vaccinated people. Three out of every four new Gold and Platinum consumer cards in the U.S. came from these age cohorts, Chief Executive Officer Stephen Squeri said on Friday. AmEx"s Platinum card comes with a spate of travel rewards including access to airport lounges and other benefits at hotels and resorts globally. "It"s that younger generation that is just more comfortable, continuing to live their lives as they were pre-pandemic than the older baby boomer generation, which continues to react much more cautiously," Chief Financial Officer Jeff Campbell told Reuters. Millennials and Gen Z users spent 48% more on their cards than they did last year, and 38% more than in the third quarter of 2019, AmEx disclosed. Its shares were up 4% at a record-high. ABOVE PRE-PANDEMIC LEVELS Spending at restaurants through AmEx cards grew above pre-pandemic levels, and is now the largest category in the travel and entertainment business, the company said. "Our view remains that across all customers across all geographies, spending on travel and entertainment is going to come back to where it was pre-pandemic," Campbell said. Net income came in at $1.83 billion, or $2.27 per share, for the third quarter ended Sept. 30, up 70% from last year and beating analysts" estimates of $1.80 per share, according to Refinitiv data. AmEx also released $393 million of reserves in the quarter. Excluding interest expense, the company"s total revenue rose 25%.