LISBON, March 3 (Reuters) - Portugal's EDP Renovaveis has raised 1.5 billion euros ($1.8 billion) in an accelerated capital increase to help fund investment to 2025, the renewable energy unit of top utility EDP said on Wednesday.

EDP last week announced plans to invest 24 billion euros ($29 billion) in green initiatives, mostly renewable power and grids in the United States and Europe, over five years, as it seeks to bring forward its push to go "completely green" by 2030.

The plan foresees EDP Renovaveis investing 19 billion euros to deploy around 20 GW of renewable energy by 2025.

"The proposed capital increase... is to partially finance EDPR's capex plan," it said in a statement.

EDP Renovaveis placed 88,250,000 shares with institutional investors, representing 10.1% of existing share capital.

Shares were placed at 17 euros apiece, 9.3% lower than the 18.74 euros EDP Renovaveis shares closed at on Tuesday.

After this capital increase, EDP will lower its stake in EDP Renovaveis to around 75% from 82.6%.

EDP shares were down 9.29% to 17 euros.

($1 = 0.8281 euros) (Reporting by Sergio Goncalves; editing by Victoria Waldersee and Jason Neely)