Twitter has disclosed plans to raise up to USD one billion from its proposed initial public offer (IPO) in its initial registration form (S-1) with the US Securities and Exchange Commission (SEC).

US-based PrivCo, a provider of business and financial research on major privately held companies, has said an earlier version of Twitter's S-1 form "inadvertently" revealed February 15 as the last date for the lock-up period for employees to sell their restricted stocks.