It was confirmed last night that former Barcelona coach Guardiola would take charge of Bayern at the end of this season.
His agent Josep Maria Orobitg said: "I don't know exactly which day, around the 20th or the second half of December."
Speaking on EFE Radio, Orobitg added: "He chose Bayern because of all the teams from which he had offers it was the best.
"We were looking over the offers and this isn't the team which offered the most money. It was chosen for the organisation there, for the potential that he sees, and for their players."
That raised the possibility that a Premier League club had offered big money to Guardiola, although AC Milan and wealthy Paris St Germain had also been credited with interest in him.
Orobitg added: "There have been things coming out from all sides that there had been offers, real meetings, false meetings, trips which didn't exist.
"From Christmas he had to choose his future. All this has been signed for some time. I didn't know that they were going to announce it this afternoon. In fact they informed me at 12 that it was coming out in a statement."