Amazon.com (Nasdaq:

) is reportedly close to acquiring Quidsi Inc., the parent company of Diapers.com and Soap.com, for $540 million, according to people with knowledge of the matter. An announcement could be made as early as Monday. Quidsi, which expects to ship 500 million diapers this year, will help Amazon cater to new parents and gain expertise in warehouse management and low-cost shipping, according to Bloomberg News. Amazon started selling diapers in 2006 following the debut of Diapers.com. Quidsi, which expects to ship 500 million diapers this year, will help Amazon cater to new parents and gain expertise in warehouse management and low-cost shipping, Bloomberg reported. Fortune reported that New Jersey-based Quidsi also received a takeover offer from Wal-Mart (NYSE:

), the world's largest retailer.