Asa Mathat/All Thing Digital, via Reuters

Groupon is entering the final leg of its long journey toward an initial public offering.

On Friday, the daily deals site disclosed that it had narrowed its third-quarter losses, to $1.7 million, and that its North American operations turned a profit.

The results are an important milestone for the company, which has been trying to quell concerns about its business model before going public.

Groupon, according to its revised prospectus, expects to sell 30 million shares and fetch $16 to $18 a share, valuing the company at as much as $11.4 billion. At the midpoint of that price range, the company could raise $510 million. Its underwriters could also sell an additional 4.5 million shares if demand exceeded expectations.

Friday’s revision was filed as Groupon and its cadre of bankers prepared for a two-week road show with potential investors, hoping to generate excitement over the company’s forthcoming I.P.O. The company had been especially keen to prove that it was at least close to profitable before it began its road show, according to people who were briefed on the matter but were not authorized to speak publicly.

Groupon expects to price its offering around Nov. 3.

Since its founding less than three years ago, Groupon has become one of the stars of the new generation of Internet start-ups. By pioneering the market for deep discounts at local restaurants and stores, the company has grown at a remarkable speed, attracting hundreds of millions of subscribers and posting sales at stunning rates.

The site now has 142.9 million subscribers, according to its latest filing, a sevenfold increase from last year. As of the third quarter, about 29.5 million of those people had purchased at least one deal.

Yet soon after the company filed its first prospectus, it attracted harsh scrutiny from skeptics of its business model and its accounting, which critics said gave a misleading impression of profitability. Groupon amended its prospectus several times, restating its revenue and removing a controversial financial metric.

It addressed apparent breaches of a mandatory “quiet period” for companies preparing to go public. The most widely known of these was a memorandum to employees written by the company’s chief executive, Andrew D. Mason, that was quickly leaked to the news media.

Though Groupon’s growth has slowed as it has grown larger and more diversified — its net revenue grew only 9.6 percent over last quarter, to $430.2 million — the company disclosed in its latest filing that it was still attracting new subscribers and converting them into paying customers.

Readying itself for potentially tough questioning from investors, Groupon’s highest priority has been to show that its business and growth are sustainable. In prospectus on Friday, the company said that the amount of coupons sold per customer had grown 27 percent year-over-year, to about 4.2. And the company’s average revenue per deal had grown about 31 percent over the same time last year, as well as about 7 percent over the second quarter.

But critics have worried that Groupon is doling out increasingly huge sums to attract new customers. In the first nine months of the year, Groupon spent $613 million on marketing, compared with less than $90 million in the same period of 2010.

The company is looking to reduce those expenses. Groupon trimmed its marketing budget in the third quarter, from the previous three months, according to a person with knowledge of the matter. Mr. Mason has promised a significant cutback in marketing expenses in the future.

Over the last year, Groupon has introduced new offerings that expand its business beyond daily deals, including travel packages and ticketed events. Those new products have diversified the company’s operations, although they often carry lower profit margins that have weighed on sales growth.

Revenue per subscriber fell 15 percent to $3.30 in the third quarter, from the previous quarter, and the company’s deal margin, or revenue divided by gross billings, shrank.

This trend is likely to continue in the near term as Groupon attracts a broader mix of consumers who may not be as engaged as the first wave of early adopters. But the company also expects deal margin to pick up again in the next quarter.

Though Groupon will spend most of its road show highlighting its growing profitability, it is also likely to trumpet one zero: the number of insiders selling shares. While earlier filings referred to “selling stockholders,” the company recently stripped that language from its prospectus, indicating that its shareholders would not sell any shares in its offering.

In recent months, the start-up has been harshly criticized for letting its founders and early investors profit, through hefty stock sales, well ahead of its I.P.O. In January, for example, Groupon raised $950 million. Of that, $810 million went straight to its shareholders.