Online retailer Amazon.com Inc said it has raised approximately $1.25bn in a private debt offering of 4.75% convertible subordinated notes due 2009. The Seattle-based company announced late Thursday that it had upped the offering from a planned $500m sale, announced earlier in the day. The deal comes two days after Amazon said it would be investing heavily in the coming quarters to build up its infrastructure and its all-important brand and is no surprise, as the company had only $25.6m in cash on its balance sheet at the end of the December quarter. The notes offered will be convertible into common stock, at the option of the holder, at a conversion price of $156.05 per share, which represents a conversion premium of 27% over Thursday’s closing price. Amazon says they have been sold to qualified institutional buyers and to certain institutional-accredited investors.