NEW YORK – Facebook will be forced by law to start coughing up details of its financial performance or go public by April 2012, a published report says.

The Wall Street Journal reported Thursday that privately held Facebook Inc. plans to cross the 500-shareholder threshold this year, citing a memo being distributed to potential investors.

That will trigger a Securities and Exchange commission rule requiring financial disclosures, even if Facebook still hasn’t had a formal IPO.

The news comes two days after a report in The New York Times that Goldman Sachs and a Russian investor have paid more than $500 million for a stake in the company — giving Facebook a value of $50 billion.

Goldman declined to comment and Facebook did not immediately reply to a request for comment.