(The unit is appealing a commission ruling that it was violating the antimonopoly law.)
A commission ruling on the merger is expected later this year.
A 1991 commission ruling, still in force, permits the building of penthouse apartments.
The commission ruling would give preference in use of the company's transmission lines to third parties, including independent power producers.
"It was unseemly," the commission ruling said, adding that the public should not have to wonder whether fines are meant to pay a justice's salary.
The commission ruling took note of the Sept. 11 attacks.
The appeals court decision should signal the court's view of the legal validity of the commission ruling.
The commission ruling resulted in a fine of 497 million euros against Microsoft and an order to change the way it sells software in Europe.
The commission ruling came two years after it had decided that all Internet activity was exempt from the campaign finance laws.
The report attacked long delays in commission rulings.