Nov 5 (Reuters) - Rivian Automotive, backed by Amazon.com Inc (AMZN.O), on Friday significantly raised the expected offer price of its shares, with the electric vehicle manufacturer aiming for a valuation of as much as $65 billion in its initial public offering. It had earlier this week aimed for a valuation of more than $53 billion at a price of $62 per share. The company now expects to sell 135 million shares in the range of $72-$74 apiece to raise nearly $10 billion on Nov. 9.The increased price band follows a successful investor roadshow this week, as Wall Street"s big IPO investors bet on Rivian to be the next big player in a sector dominated by Tesla (TSLA.O). The IPO could make Rivian one of the only three companies that have raised more than $8 billion in a decade after Alibaba (9988.HK) and Facebook (FB.O). While the startup has yet to sell any significant volume of its electric vans or trucks, a $65 billion valuation for Rivian could make it more valuable than Fiat maker Stellantis NV and bring it closer to legacy automakers Ford (F.N) and General Motors (GM.N). Rivian has been investing heavily to ramp up production, including for its upscale all-electric R1T pickup truck which was launched in September, beating out competition from established rivals such as Tesla Inc, General Motors and Ford. The company had about 55,400 R1T and R1S preorders in the United States and Canada, as of Oct. 31. Rivian said it had started deliveries of the R1T and had recorded revenue for the three months ended September 30. Net loss for that period, however, is estimated to increase due to higher production costs. The EV market is booming as consumers are more environment conscious and is seen as a symbol of luxury for many brands. Tesla produced a record number of cars in its latest quarter, suggesting strong demand for electric cars. Amazon has ordered 100,000 of Rivian"s electric delivery vans as part of the e-commerce giant"s broader effort to cut its carbon footprint. Rivian will, however, face competition from automakers in both the consumer and commercial van markets. Ford said it has more than 160,000 orders for its F-150 Lightning electric pickup truck and that an electric version of its Transit commercial van is "completely sold out." General Motors is gearing up production of electric delivery vans, SUVs and pickup trucks. Morgan Stanley, Goldman Sachs and J.P. Morgan are the lead underwriters. Rivian will list on the Nasdaq under the symbol "RIVN". The valuation includes shares that underwriters could exercise under the "greenshoe" option.