VIENNA, Dec 4 (Reuters) - Property tycoon Rene Benko's Signa Holding filed for insolvency in Vienna last week, the biggest such case Austria has seen and the largest victim to date of Europe's property crash.

Benko, 46, built the complex constellation of companies headed by Signa Holding from the ground up, starting from humble origins in the western city of Innsbruck. Signa is an owner of New York's Chrysler Building as well as high-profile projects and department stores across Germany, Austria and Switzerland.

THE PROCEEDINGS

The company has filed for insolvency seeking to administer itself through its restructuring. Under Austrian law it must repay at least 30% of the amount it owes to its creditors, or 1.5 billion euros ($1.6 billion) according to the data currently available, within two years.

Clarity must be established within 90 days on whether and how that can be done. If the company cannot be restructured, it will be liquidated.

Below are key steps set by the court overseeing the process.

FIRST CREDITORS' MEETING

At the first creditors' meeting on Dec. 19, court-appointed administrator Christof Stapf will give an initial assessment of whether Signa's financial and restructuring plans are realistic.

Currently Signa is continuing to manage its business under his supervision. Stapf has the power to decide the company can no longer administer itself, though the Vienna court where Signa filed for insolvency, which appointed Stapf, has the final say.

Creditor protection groups have said it would be a "Herculean task" to determine the value of the hundreds of companies that are part of the group overseen by Signa Holding. That will, however, be an essential part of Stapf's job.

CREDITORS' DEADLINE

Creditors have until Jan. 15 to declare their claims against Signa. So far there are 273 known creditors with claims totalling roughly 5 billion euros. The precise figure will become known during the proceedings.

SECOND CREDITORS' MEETING

As part of the second creditors' meeting on Jan. 29, Stapf will declare which claims by creditors are formally recognised and which are disputed.

THIRD CREDITORS' MEETING

Creditors meet on Feb. 12 to vote on a restructuring plan that will have been drawn up by then.

A simple majority of creditors and of the amounts they claim is required. If the restructuring plan is approved, the remaining debts not due to be repaid under the plan are forgiven. If the plan is not approved, liquidation follows. ($1 = 0.9249 euros) (Reporting by Francois Murphy; Editing by Alex Richardson)