Aulas told French newspaper Le Progres the offer from the Hammers was the biggest so far tabled for the striker
The 24-year-old France international has been a prolific scorer for Lyon in the French league for three seasons
West Ham will move from Upton Park to London's Olympic Stadium for next season
Aulas was asked if Lyon had received offers for Lacazette, and said: "Yes
Many, the most important being that of West Ham for 40 million euros (£31million) which we've refused
I want to keep him but I'm not certain because it's he who will decide in the end."
Aulas detailed Lyon's position, telling the newspaper: "To have a sale, you need all three parties to be in agreement
We hope to keep him
Now, if there are offers..
"Last season I expect Monaco wanted to keep (Anthony) Martial (who moved to Manchester United)
"What I don't want is that, by August 28, when we've qualified for the Champions League, we find ourselves in the same situation
"If there's an offer he can't refuse, he'll come to see me."
Source : PA
Source: PA