Warplane maker Irkut said it would list shares in London only after the formation of the United Aviation Company, a holding company planned by the Russian government to revive the ailing aerospace industry.

President Vladimir Putin in February ordered the merger of state owned Russian planemakers into UAC, in which the state intends to hold no less than 75 percent. In addition, private companies including Irkut will have to swap controlling stakes in their companies for UAC shares.

The UAC is expected to be registered in late September and all UAC assets finally consolidated by the first quarter of 2007, senior industry officials assured Putin last month.

Irkut had said earlier that it planned to list some of its shares in the form of second or third level American Depositary Receipts on the London Stock Exchange during 2006.

Any operations with shareholder capital and debt instruments should be concluded in a stable situation, Irkut Vice President Dmitry Yeliseyev told Reuters, giving the reason for the delayed share issue.

Irkut makes the flagship Sukhoi fighter jets but wants to grow further and expand globally beyond Russia's traditional Cold War era markets in Asia. It has already floated 23 percent of its shares in Moscow.

The company, which had also planned to issue at least $150 million (80 million pounds) in Eurobonds, reiterated it would go ahead with its listing plans and that the situation would become clear in the first quarter of 2007.

This (share issue) is a natural way of development, Yeliseyev said. And certainly, a third level ADR appears to be the most optimal one. He declined to give an approximate date for the issue.

Russian defence companies are banned from selling more than 25 percent of their shares to foreign investors, but Yeliseyev reiterated he hoped the government would drop that requirement.

European aerospace and defence giant EADS has bought a 10 percent stake in Irkut and is now set to become the primary foreign partner in the newly created UAC holding.