Pedro is eager to move on from Barca following his struggles to get regular game-time ahead of the superstar trio of Luis Suarez, Neymar and Lionel Messi.
United were understood to be closing in on a £22m deal for the Spanish winger.
But now, The Mirror cite reports in Munich-based newspaper TZ that say the 27-year-old wants a reunion with former Barca boss Pep Guardiola.
TZ have revealed that Bayern's interest is real and the Bundesliga champions are considering a swoop for him.
The news comes as a major shock to United who had thought they had their deal wrapped up.
United executive vice-chairman Ed Woodward has returned to the UK to finalise the transfer, that would see the club take their summer spending over the £100m mark.
But, with Bayern's surprise interest, Pedro's future is still unclear.
