LinkedIn has confirmed its plan to go public in 2011 and is seeking to raise $175m in what will be the first US social network IPO.

LinkedIn also plans to boost the way advertisers can target members and will offer them more options following recent reports that LinkedIn ads do not perform very well.

LinkedIn, which is the largest professional-social networking site ahead of rivals Xing and Viadeo, has hired Morgan Stanley, Bank of America and JPMorgan Chase to lead the offering, according to a filing with  the US Securities and Exchange Commission.

As the first social network to float in the US, although Xing floated in Germany back in 2006, it is likely to attract a lot of interest.

LinkedIn currently has around 90 million members which is up by around 30 million on this time last year.

LinkedIn’s current shareholders include co-founder Reid Hoffman with 21% percent; Sequoia Capital with 19%;  Greylock Partners with 16% percent; Bessemer Venture Partners with 5.1%; and LinkedIn CEO Jeff Weiner who owns 4.1%.

News of the IPO comes as LinkedIn announces plans to update advertising features on the network to allow advertisers to target ads at people based on job title, age and location, according to a report in the Wall Street Journal.

LinkedIn, who major advertisers include Hewlett-Packard and American Express, does not currently offer the kind of social advertising options that are available on rival social network such as Facebook and it is keen to boost  ad revenues.

Advertising currently accounts for less than a third of LinkedIn’s income, which stood at $161 in the 9 months to September, with the bulk of its revenues coming from recruitment.

* 45% of its revenues, or $28 million from recruiting
* 29%, or $18 million  from advertising,
* 24%, or $15 million from subscriptions