Berkeley's share price was 742p earlier this week.
Berkeley said the issue was needed to fund 10 joint ventures that were close to being agreed, rather than use debt to fund them.
It added that it was also in negotiations to with two major landowners to develop land under its control.
A spokesperson said: "The proceeds of the placing will enable Berkeley to finance these joint ventures without denying financial resources to the ongoing activities of the group – and without placing undue demands on the borrowing levels of the group."
Peel Hunt analyst Stephen Rawlinson said the move made sense for Berkeley.
He said: "Managing director Tony Pidgley needs cash for his deals and doesn't want to muck around. This will give it to him."
On 31 October 2001 Berkeley's debt was £253m (excluding £47m in joint ventures) with a gearing of 28%. At the end of last year Berkeley's debt stood at £3366m. The firm released a trading update this week, which said trading this month and last had been very strong, with sales up on the same period last year.