Real estate magnate William Lyon and his son, bidding to bolster their home building empire by acquiring Presley Cos., have waived the minimum-share requirement in their bid for up to 10.7 million shares of Presley stock. The offer initially depended on a minimum of 1.99 million shares being tendered, William Lyon Homes said Friday in a press release. Although the deadline for accepting the offer of 65.5 cents a share has not lapsed, Lyon decided to proceed with the deal, regardless of whether the minimum number of shares are tendered, according to a source familiar with the deal. Presley's stock was unchanged Friday, closing at 75 cents a share on the New York Stock Exchange. Under the complex transaction, Presley would acquire Lyon's privately held firm, William Lyon Homes, for $48 million, and assume $30 million in debt. In turn, Lyon and his son, William, offered to acquire the Presley shares for $6.9 million. The full purchase would increase Lyon's stake in Presley from 22% to about 49%. Lyon plans to combine the Newport Beach-based companies. The elder Lyon already is chairman of the two firms.