The young striker is one of the world's hottest properties at the moment, with United, Inter Milan and Real Madrid among the clubs reportedly considering a 40 million euro bid.
Favourites to land the 21-year-old. United are ready to use some of the money earned from the impending sale of Cristiano Ronaldo to bring Benzema to Old Trafford, however, Lacombe insists he has not received any offers as yet.
"The fax is not overheating," he told le Dauphine Libere. "Even if you should never say never in football, there is a lot of noise about nothing at this moment.
"The idea is still to keep Karim for another season."
Benzema's agent has also confirmed the France forward is keen to remain at Lyon for another year at least before seeking a move to a bigger club.
"OL don't need liquid assets and Karim wants to stay until the 2010 World Cup," said Karim Djaziri. "On our part a departure is not on the agenda."
Benzema, who has come through the ranks at the Ligue 1 giants, scored 23 goals in all competitions this season - an average of a goal every other game.
Meanwhile United have made a £17.5 million offer for Wigan winger Antonio Valencia.
Sir Alex Ferguson is said to have been tracking the 23-year-old since the start of the year, and according to Wigan chairman Dave Whelan, bnegotiations are underway.
"They [United] have been in touch with us and we will be starting negotiations very shortly, I would imagine," he said. "United have been in touch with us over Antonio for the last two or three months, expressing an interest and actually putting cash offers on the table."