The Premier League club, which is controlled by the Glazer family, may start the road show as soon as Friday or early next week, according to the sources. The offering is expected to value the team at roughly $3 billion.
But sources warned that market conditions could lead to further delays.
The S&P 500 fell for the fourth day on Wednesday amid worries about the European debt crisis and earnings, and the volatility has already led to at least one delay. Sources familiar with the situation said on Tuesday that the club was planning a launch earlier this week but delayed it because of market conditions and was going to re-evaluate conditions.
If the launch happens as planned now, the club could price the offering in the week of August 13, the sources said.
Manchester United could not be reached for comment.
The offering is being watched closely by millions of the club's fans, who follow the team with almost religious fervour.
The Glazers, who took control of the club in 2005, have been reviled for saddling up the team with too much debt, leading to fears that it would not be able to attract the best soccer players. The team has £423 million of debt, which the owners hope the IPO will help reduce.
In 2010, a group of wealthy Manchester United fans known as the Red Knights, which included Goldman Sachs chief economist Jim O'Neill, tried to buy the team for 1 billion pounds, arguing that the team's value was in decline.
The Glazer family, better known in the United States as owners of American football team the Tampa Bay Buccaneers, made their fortune owning and leasing shopping centres. The family will remain in control of the team after the offering through the use of a dual-class structure in which the Glazers' shares will have 10 times the voting power of average investors' shares.
Their attempts to take the club public have, however, run into trouble. The team scrapped plans to list in Hong Kong and Singapore after demand came in weaker than expected. It had originally looked to raise as much as $1 billion in Singapore.
Morgan Stanley, which was one of the underwriters for the offering planned in Singapore, dropped out of the syndicate for the US IPO due to concerns that the valuation the team was seeking was not realistic, sources have previously said.
Now, Jefferies Group Inc is the lead book runner in the syndicate, which also includes Credit Suisse, JPMorgan Chase, Bank of America Merrill Lynch and Deutsche Bank.
The banks plan is to benchmark Manchester United against both traditional media companies as well as consumer goods companies. There have historically been few publicly traded sports teams in the US, with the exception of the Boston Celtics and Cleveland Indians - both now privately held.
The company is slated to be listed on the New York Stock Exchange under the ticker "MANU."