Venoco founder Tim Marquez has been given a second extension until Aug. 31 to tell shareholders how he plans to come up with as much as $400 million to take his company private.

The Denver-based oil company has large operations on the South Coast and was formerly headquartered in Carpinteria. Marquez, who remains CEO until Aug. 1, made a bid to take his company private last year in a deal that would value the company at around $770 million, not including debt.

Shareholders approved that bid on June 5, and Marquez had until June 12 to reveal how he could finance the cash portion of the deal. Venoco’s board granted Marquez an extension until July 20 to show financing plans. On July 20, the board granted another extension. Marquez has until Oct. 16 to close the deal. Venoco’s stock declined 13 percent to $8.50 in the five days following the announcement of the news.

Meanwhile, the planned succession of Ed O’Donnell from chief operating officer to chief executive officer is expected to take place on Aug. 1.  With the promotion, O’Donnell’s base salary of $403,000 this year will rise to $675,000, along with sweetened performance incentives.