BEIJING, Nov 3 (Reuters) - China's state planner issued draft guidelines on Friday for Chinese companies investing overseas, aimed at improving oversight, safeguarding national security and increasing support, the government said in a statement.

The statement issued by the National Development & Reform Commission builds on previous regulations released in 2014.

China's non-financial outbound direct investment has plunged this year as authorities keep a tight grip on outflows for what they call "irrational" overseas projects. The grip is part of efforts to curb speculative capital outflows that had pressured the yuan currency. (Reporting by Beijing news monitoring and Christian Shepherd; Writing by Josephine Mason; Editing by Kim Coghill)