In a short statement on Zenit's official website, the club announced the agreement with Advocaat had been extended until the end of 2009.

A verbal agreement on a new deal was believed to have been reached between Advocaat and the Russian club last month, with formalities completed on Friday.

Since joining Zenit in July 2006, the Dutchman has led the club to their first Premier Liga title as well as UEFA Cup and Super Cup successes.

Emulating last season's achievements, however, has proved difficult.

Zenit improved their chances of progressing to the final stages of this season's Champions League with a 2-0 win at BATE Borisov on Wednesday, their first victory in Group H.

But with Juventus already safely through from that pool, much will depend on their encounter with Real Madrid at the Bernabeu on December 10.

At domestic level, Advocaat's men lie fifth in the Premier Liga and, with only three games remaining, face a fight for third place and the final Champions' League berth with Dinamo Moscow and Amkar Perm, both of whom they are still to play.

In signing on for another year, Advocaat is also likely to face several personnel changes for the next campaign.

Andrei Arshavin has reiterated his desire to move abroad at the end of the season, and there are question marks over the future of South Korean midfielder Li Ho and striker Pavel Pogrebniak, who has been linked with a move to Jurgen Klinsmann's Bayern Munich.

Veterans Vladislav Radimov and Aleksandr Gorshkov are also set to retire at the end of the campaign.

"Only after the Real match will we be making decisions regarding the players", Advocaat said ahead of his side's match in Perm against Amkar on Sunday.

"We'll be holding meetings between the players and the management and we'll discuss these questions together."