* Intends to sell 70 mln shares priced between $17 and $20
* Seeks to avoid a repeat of Facebook's bungled IPO
* Stock could begin trading as soon as Nov. 7
SAN FRANCISCO, Oct 24 (Reuters) - Seeking to avoid a repeat of Facebook Inc's much-maligned public debut, Twitter Inc revealed more modest ambitions on Thursday, saying its initial public offering would raise up to $1.6 billion and value the company at up to $10.9 billion.
The valuation was more conservative than the $15 billion that some analysts had expected for the social media phenomenon.
Twitter, which has signaled for weeks that it would price its IPO conservatively to avoid the stock drop that marred Facebook's offering, said that it intends to sell 70 million shares priced between $17 and $20.
If the company's underwriters choose to sell an additional allotment of 10.5 million shares, Twitter could raise as much as $1.6 billion at the top of the price range, according to an amended version of its prospectus filed on Thursday.
Twitter is expected to set the price on Nov. 6, according to a document reviewed by Reuters, suggesting that the stock could begin trading as early as Nov. 7.
"It's conservative and likely going to be raised as they start the road show at least once if not twice," Sam Hamadeh of PrivCo, a private company research firm, said of Twitter's pricing.
"The size of the offering is also a bit small," he added. "But they may only choose to raise the price once they gauge investor demand. Raising both the price and the size was Facebook's fatal mistake."
Twitter said on Thursday that there will be 544,696,816 shares of its common stock outstanding after the offering.
Twitter's offering is the most high-profile Internet IPO since Facebook's rocky debut in May 2012, in which the company's shares fell below their offering price in the ensuing days.
The company and its underwriters will begin a two-week road show on Oct. 28 in New York and will stop in Boston and the mid-Atlantic region before touching down in Chicago, San Francisco, Los Angeles and Denver, according to a source familiar with the offering.
The company could choose to raise the price of the offering during that period after gauging investor interest. In the case of Facebook, the company initially priced its shares at a minimum of $28 before ultimately raising it to $38 shortly before listing. Aside from raising the share price, Facebook also increased the size of its float - something that one out of 20 companies choose to do before their IPO, according to PrivCo's Hamadeh.
Twitter, which has roughly 230 million active users, has said it plans to list its stock under the "TWTR" symbol on the New York Stock Exchange.
The eight-year-old company more than doubled its third-quarter revenue to $168.6 million, but net losses widened to $64.6 million in the September quarter, it disclosed in a filing earlier this month.