Air Berlin may announce more details of its upcoming IPO tomorrow.It is expected that the carrier's stock could begin trading as early as May 5. According to German daily Boersen-Zeitung, a possible press meeting Friday will signal the start of the road show for the offering, which includes a visit by CEO Joachim Hunold to the US to attract interest from Wall Street in the German low-fare airline.

Another newspaper, Sueddeutsche Zeitung, is reporting that around 50% of the company will be floated, with a total transaction value of between ?700 and ?900 million ($858.6 million-$1.1 billion), which is higher than had been expected.