Neath are refusing to comment on the deal - understood to be three years - until it is complete.
It would mark a sensational return to the Welsh Premier where Trundle first made his name at Rhyl before joining Wrexham then Swansea and Bristol City.
Trundle had offers from Football League clubs including League One side Yeovil Town and was also linked with Blue Square Bet Premier new boys Newport County.
He scored 11 goals in six appearances for Rhyl before being plucked by then-Wrexham manager Brian Flynn in a £60,000 move.
When Flynn moved to Swansea, Trundle followed on a free transfer in the summer of 2003.
It was there where he became an instant hit with supporters who named him "Magic Daps" and during a four-year spell, Trundle scored 78 goals in 146 appearances.
It earned him a £1m move to Bristol City but found it difficult to hold down a regular first-team place and in the last of his three years there, he was loaned back to the Swans.
Bristol City released Trundle this summer and the Swans offered him a only coaching role, which he turned down in order to keep playing.
Source: BBC Sport
Source: BBC Sport