Nathaniel, chief executive of NVA Management, has been liaising with a group of entrepreneurs and an official bid was lodged on Friday.

With owner Mike Ashley looking to sell the club, there was reported interest from South Africa over the weekend, with the Nigerian consortium insisting they will not be embroiled in a bidding war.

"We have put a bid in on Friday evening," Nathaniel told PA Sport.

"We are now looking at things around improving the football club in anticipation of hearing back from Newcastle positively.

"Therefore, the consortium have asked to look at areas of how we can improve the club while Newcastle are considering the bid."

Joe Kinnear has been appointed interim manager and Nathaniel's priority is to find a suitable permanent boss, with Keegan's standing among Newcastle supporters acknowledged by the potential buyers.

City sources have suggested a degree of scepticism over the Nigerian consortium, particularly as they will remain anonymous until a bid is accepted.

Nathaniel insists they are serious, with a long-term strategy for the club already being worked on.

"As far as I know we are the only official bid to have been put in," Nathaniel added.

"I'm sure they will wait for other bids and make a decision on which one to accept.

"One thing is for sure, we will not get involved in a bidding war. We've earmarked money for transfers, money to buy the club and money to deal with the various deep-rooted issues behind the club like the academy.

"A budget has been put in place and my instructions are that they do not want to go over that budget."

Seymour Pierce chairman Keith Harris has been appointed by Ashley to sell the club, but in the meantime Kinnear is in charge of a team in freefall.

They are second from bottom in the Barclays Premier League and next face Everton, Manchester City and bitter rivals Sunderland.

"Everything in life snowballs," said skipper Michael Owen.

"If you win it becomes a habit and if you lose it becomes a habit.

"You can see people curling up and shrinking in a way and vice-versa when you play well - you see people wanting the ball and making angles.

"It's never been any different. I've been in teams that are low on confidence and in teams that are flying high and feeling invincible.

"Once confidence goes it's hard to get out of that rut.

"We need some confidence - it is lower than a snake's belly at the moment."

Kinnear can take heart from Owen's five goals this season and the performance of Damien Duff in the defeat to Blackburn at the weekend.

"He's got the ability to run at people, and he can pick out a pass as well," Kinnear said.

"We don't want to be passing it to him when there's people marking him, but when the full-backs are dropping off.

"We want him to beat people, and have people on the end of his crosses."