Airbus has expressed concern about the implications of part of the EC's antitrust decision against Microsoft and has filed a petition with the court handling the appeal.
"Airbus is seeking a clarification of one of the points raised in the [EC] decision related to market regulation," a spokeswoman for the company said, although she emphasised that Airbus was not taking sides.
A report published in the online edition of The Wall Street Journal on Friday (17 September) said that Airbus feared that the EC ruling could affect the way it makes planes by thwarting its choice of providers for components such as seats and galleys.
Earlier this year the commission found Microsoft guilty of improperly using its dominance in PC operating systems to boost its hand in other markets. Microsoft is appealing the decision.
As part of the appeal process, interested third parties are allowed to intervene and question points of law, according to Anthony Woolich, an antitrust layer with legal firm Lawrence Graham.
"It is very important to get support to show that it is not just the [appealing] party's personal commercial interest at stake, that there is a wider point of principal," Woolich said.
That Microsoft should try to get third parties to intervene is of little surprise, given the magnitude of the case, Woolich added.
Microsoft has approached Airbus rival Boeing and encouraged it to intervene also, the The Wall Street Journal reported.
In its antitrust ruling, the EC ordered Microsoft to pay a €497m (£338m) fine and gave it 90 days to begin selling a version of Windows in Europe without its Media Player software. It also gave the company 120 days to reveal enough Windows source code to allow rivals to build competing server software that works properly with Windows.
Microsoft filed its official appeal against the decision with the EU's Court of First Instance (CFI) in June. A spokesman for the court declined to give any details of the Airbus petition.
Although the EC decision is specific to Microsoft it creates case law that could have a wider-ranging effect on how companies deal with competition.
"If Microsoft can gain support from third parties who say that customers are being adversely affected by the decision, that can be very, very compelling," Woolich said.
The EC decision came after what was widely considered as a slap on the wrist to Microsoft from US antitrust authorities.
Woolich warned, however, that the EU's antitrust case is far from over. Appeals to the CFI often take one to two years, and its decisions can be appealed to the European Court of Justice, he said. Appeals to that court often take two to three years, he added.
"Realistically it could be five years before this case is settled and the technology would have moved on," Woolich said.
Scarlet Pruitt writes for IDG News Service