Virgin offers no guarantees on Tiger fleet Virgin Australia insists it cannot give an ""iron-clad guarantee"" that it will triple the size of Tiger's Australian fleet within the next five years because of the volatile nature of the industry. The competition regulator has indicated that one of the conditions of it approving Virgin's bid for a controlling stake in Tiger Australia could be it living up to plans to boost the budget airline's fleet from 11 to 35 planes by 2018. But speaking after Virgin posted a more than halving in first-half profits, the chief executive, John Borghetti, said it would be irresponsible to give a firm commitment to boosting Tiger's fleet to 35 planes because it operated in a ""very volatile industry"." ""You can't give an iron-clad guarantee on something like that because you just don't know what's around the corner,"" he said. ""No airline in the world would give a capacity commitment for five years."" The airline's bid for Tiger, and approved takeover of regional airline Skywest, threatens to reshape Australia aviation market by effectively returning it two a duopoly. Virgin and Tiger's Singaporean parent appear to be replying on the so-called ""failing business"" argument to win approval from the regulator, although their case has not been helped by the budget airline recently adding new routes to its Australian network. Tiger's Singaporean management has also intimated that they will pull their airline out of Australia if the Australian Competition and Consumer Commission does not approve the deal. Profit hit by competition Virgin's refusal to make a firm pledge came as its net profit fell by 56 per cent to $23 million in the first half due to a ""capacity flood"" in the domestic market and the impact of the carbon tax. The bottom-line result was lower than analysts had expected, resulting in a 4 per cent slide in Virgin's share price. Pre-tax earnings from Virgin's core domestic business fell by 44 per cent to $49 million in the first half, as it faced the biggest increase in capacity since the launch of Jetstar nine years ago. However, Mr Borghetti said what had been clear over the last eight months ""is that we have withstood the most strong competitive response that I have seen in this market for a very long time"." While the corporate market had remained ""relatively resilient"" in the first half, the leisure segment had been ""a little bit more fickle"." The airline has not made a second-half profit for five years because it ""was hostage to the leisure market"" but it is hoping that its aggressive push into the corporate travel market will help make earnings more even over the financial year. Boost to capacity Virgin plans to boost capacity in the domestic market by 5 to 7 per cent in the second half, compared with the same period in 2011-12. However, Virgin's capacity is almost unchanged when compared with the first half. Qantas indicated last week that the capacity glut in the domestic market has eased since January. Mr Borghetti said Virgin had continued to boost its share of the corporate travel market, and ""maintained the new norm"" in which more than 20 per cent of its revenue came from the higher-yielding segment. Virgin's international operations reported a 9 per cent rise to $35 million in pre-tax earnings as they began to reap the benefits of its alliances with airlines including Etihad and Singapore Airlines.