The competition regulator has indicated it will give its blessing to Virgin Australia's alliance with Singapore Airlines, the final plank in the Australian carrier's international strategy.

In a draft decision released today, the Australian Competition and Consumer Commission said the Singapore alliance was unlikely to result in "signifiant anti-competitive detriment" in any of the markets in which the two airlines compete.

Shares in Virgin rose 0.5 cents to 32 cents in early morning trading, slightly better than the rise in the broader market.

The competition regulator's draft decision to allow the alliance to go ahead is not a surprise because it is similar to Virgin's earlier deals with Air New Zealand, Etihad and Delta - all of which gained approval.

The ACCC said it believed the Singapore Airlines alliance was "likely to result in material benefits to the public, including enhanced products and services". The regulator also said the deal was likely to make Virgin more competitive with other airlines, including Qantas.

The deal is the final plank of Virgin's plan to widen its international reach.

The four airline alliances are central to Virgin's plans to become an upmarket competitor to Qantas and secure about 20 percent of Australia's corporate travel market.

Virgin and Singapore Airlines had earlier told the competition regulator that they would look at opening new routes, using bigger aircraft and boosting flight frequency to Asia if they won approval.

The deal had raised some concerns it could lessen competition but all bar one of the submissions to the ACCC had been supportive of the alliance.

Qantas decided not to stand in the way, emphasising the need for alliances to overcome competition from government-owned airlines and the tyranny of distance.