Australia's construction giant Leighton Holdings confirmed Monday it had received a letter from its major shareholder, Germany's Hochtief, announcing its intention to boost its stake in Leighton. Hochtief Australia Holdings announced its intention to make a cash offer of 22.15 AU dollars (20.07 U.S. dollars) a share to acquire three out of every eight shares held by Leighton shareholders. If all Leighton shareholders accept the offer, Hochtief will increase its stake in Leighton to 74 percent from 59 percent for about 1.15 billion AU dollars (1.04 billion U.S. dollars), Hochtief said. Hochtief also said it intends to increase its representation on the Leighton board to reflect its majority interest in the company. The company said it continues to support Leighton's chairman Robert Humphris. Hochtief plans to work with the Leighton Board to complete a broad-based review of Leighton's operating model that is being undertaken by Leighton management. In a statement, Leighton said its directors will consider the bid once it has been received.