After the United Kingdom’s Advertising Standards Authority ordered Nike U.K. to halt sponsored tweets of two of its athlete endorsers, the company has appealed the decision to the ASA’s independent reviewer.

In June, the ASA concluded that consumers could not readily determine whether tweets by two Nike-sponsored soccer players – also known as footballers across the pond – were marketing communications for Nike or merely personal statements by the players. Wayne Rooney tweeted, “My resolution – to start the year as a champion, and finish it as a champion…#makeitcount” and Jack Wilshere stated, “In 2012, I will come back for my club – and be ready for my country. …#makeitcount” Make It Count is the name of a Nike campaign to promote Nike Fuel, a new line of products.

Nike argued that the Twitter followers of the footballers would not be misled about the relationship between the company and the players, as it was well known that both were sponsored by Nike. In addition, Nike said that because the Nike URL was included in the tweets, followers could differentiate between the marketing tweets and non-marketing tweets by the players, which did not refer to their professional capacity as footballers and did not contain the Nike URL or the “#makeitcount” hashtag.

But the ASA disagreed, saying that the Nike reference was not prominent and could be missed by a Twitter user scrolling quickly through his or her Twitter feed each day.

“We considered there was nothing obvious in the tweets to indicate they were Nike marketing communications,” according to the decision. “In the absence of such an indication, for example #ad, we considered the tweets were not obviously identifiable as Nike marketing communications.”

Because the ASA determined the tweets violated the UK’s advertising code by failing to be recognizable as marketing communications, it ordered Nike to halt the ads and ensure that its future advertising was “obviously identifiable as such.”

Nike appealed the decision to the ASA’s independent reviewer, saying the company does “not believe that Twitter followers were misled because it was clear that the messages were connected to Nike’s ‘Make it count’ message.”

Announcing its decision to appeal, Nike emphasized the “evolving” guidance in the area of Twitter marketing. A spokesperson for the ASA disputed Nike’s comment, however, telling Advertising Age that “This is not a new, uncharted area. The tests were very much the same as the ones we use elsewhere on the Internet.”

To read the ASA’s decision, click here.

Why it matters: The decision marked the first time the ASA upheld a complaint involving Twitter and was shortly followed by a similar decision, where the ASA upheld a complaint against a hairdressing chain which encouraged an actress to tweet about her free haircut. The ASA said that without using a hashtag like “#ad” or “#promo,” the tweets were not obviously identifiable as marketing communications.