Although Villa remain in a relegation fight in the immediate future, Bent was persuaded to leave sixth-placed Sunderland in a deal that breaks Villa's transfer record.

"We are absolutely delighted to have him here and we know he will be a tremendous asset for the months and the years ahead," Houllier said.

"His arrival sends out a clear message about the ambition of our football club. We've brought him down here to spearhead our efforts and to help build something strong and lasting at our club."

The signing, for a fee of at least £18million, also represents a strong endorsement of Houllier, who has spent much of his tenure to date at Villa Park under pressure.

"Darren's arrival is a key element of our football strategy and philosophy, which the chairman Randy Lerner and chief executive Paul Faulkner and I have discussed since my appointment as manager," Houllier added.

"This is what we want to do, to try to implement, and we know it will take time."

Bent put in a transfer request at the Stadium of Light yesterday to push through the deal, and said he never had any doubt he wanted to join Villa.

"I'm delighted to join Aston Villa," he said. "This is a big, big opportunity for me.

"I had some good times at Sunderland, but that's all behind me now and I'm just looking forward to getting going. We have a tough, tough game now against Manchester City and if I can play, hopefully I can help to start getting some points on the board."

The former Tottenham man also denied that he was taking a step down.

"Sunderland are having a fantastic season and I had great times there but at the same time I believe Aston Villa's position is false.

"This is a new challenge for me and as soon as I knew they were interested, I knew it was something I wanted to be part of."

Houllier claimed that Bent, who turns 27 next month, is now entering his prime as a player.

"There are not many English players that have the pedigree and finishing class that Darren has shown over a number of years in the Premier League," he said.

"In the Barclays Premier League I think only Wayne Rooney and Didier Drogba have scored more Premier League goals.

"Darren is just 26 years old and is just entering the prime of his life as a striker, so he fits the bill of what we want to build here."

Former Sunderland and Villa striker Kevin Phillips yesterday suggested Bent's transfer request "boils down to pure money", but Bent denied the move was motivated by financial reasons.

"Everyone has got different opinions as to why I've come to Aston Villa Football Club," he said.

"I've showed in the past, when I could have gone to West Ham for a lot more money but I chose Spurs for footballing reasons.

"I've done the same here. I had a good time at Sunderland but I believe that time's over and I'm at Aston Villa now and I just can't wait to get going."

He added: "With Stewart Downing, Ashley Young, there's a fantastic supply line. It' just up to me to work on my finishing and try to put the chances away."

Houllier believes the transfer fee shows the club are fully behind him despite Villa's struggles.

The Frenchman said: "If you buy a player of that calibre that means the chairman is backing you - financially and also I would say from a footballing point of view. I think his arrival is a major coup for the club."

Houllier denied, however, that some of the other big names at Villa would be on their way out, quashing talk of possible exits for Downing and Young.

"They're not or sale - simple as that," he said. "Stewart and Ashley... they won't be leaving. No, not at all. They're rumours."

He added: "I think we have got a good squad and we will hopefully escape relegation.

"I don't think we were particularly lucky until now but every player who has come in will contribute to the success of the club."