(Adds details, quotes)

RIYADH, May 20 (Reuters) - U.S. private equity firm Blackstone BX.N and Saudi Arabia's main sovereign wealth fund said on Saturday they planned to create a $40 billion vehicle to invest in infrastructure projects, mainly in the United States.

Blackstone and the Public Investment Fund (PIF) signed a non-binding memorandum of understanding for the project, which will depend on further negotiations.

The proposed venture was announced during the visit to Riyadh of President Donald Trump, who has said he wants to rebuild crumbling U.S. infrastructure.

Blackstone said it expected the vehicle to have $40 billion of equity commitments, with a $20 billion anchor investment from the PIF with the rest from other investors. Through this equity plus debt financing, Blackstone expects to invest in more than $100 billion of infrastructure projects, it said.

The new fund "reflects our positive views around the ambitious infrastructure initiatives being undertaken in the United States as announced by President Trump," the PIF's managing director Yasir al-Rumayyan said.

Blackstone president Hamilton James said: "This will create well-paying American jobs and will lay the foundation for stronger long-term economic growth."

(Reporting by Andrew Torchia; Editing by Alison Williams and Helen Popper) ((andrew.torchia@thomsonreuters.com; +9715 6681 7277; Reuters Messaging: andrew.torchia.thomsonreuters.com@reuters.net))

Keywords: USA TRUMP/SAUDI BLACKSTONE GROUP