Party leader Nigel Farage said standing candidates across the country could increase the chances of another EU referendum taking place.
But he said the party would stand against all other parties - and focus on taking seats off Labour.
He had previously pledged to field more than 600 election candidates.
He said Prime Minister Boris Johnson's commitment to strike a trade deal with the EU without "regulatory alignment" was a "huge change" in the Conservatives' approach to Brexit.
Conservative Party chairman James Cleverly welcomed the move, adding the Brexit Party had recognised the risk of "preventing a stable majority government".