(Reuters) - Airtable, the U.S. cloud collaboration start-up whose backers include actor Ashton Kutcher and venture capital firm Benchmark, is in talks with investors to raise more than $200 million at a roughly $5 billion valuation, people familiar with the matter said. Such a valuation would almost double the $2.6 billion the San Francisco-based company was worth in a funding round announced in September, underscoring the growth in its business during a period of widespread work-from-home during the pandemic. The sources requested anonymity as the matter is private. Airtable, which is formally know as Formagrid Inc, declined to comment. Airtable was founded in 2012 and sells spreadsheet-like software in competition with the likes of Microsoft Excel. More than 200,000 companies use Airtable’s platform, including Netflix Inc, Expedia Group Inc and Shopify Inc, according to its website. The company has raised $355 million from investors including D1 Capital Partners, Coatue Management and Thrive Capital.