The 25-year-old New Zealander was released from his Thorneyholme Road contract last night following an emergency meeting between Accrington officials and a delegation from Nottinghamshire.
Astle said he wished to take the opportunity Nottinghamshire had offered him and after three hours agreement between both parties was reached.
``Officials of the club are devastated,'' said Peter Barratt, chairman of Accrington CC's management committee.
``Nathan expressed the desire to further his career and play at a higher standard of cricket.
``We understand that's his business, his craft and we are not going to stand in his way.
``It wouldn't do us any good to do so.
``We don't want a professional who is not 100 per cent happy at Accrington.''
Accrington must now seek to replace a man who had amassed 327 runs and claimed 16 wickets in the Lancashire League, which he did despite missing several games on international duty.
``It's a very difficult position for the club,'' added Mr Barratt.
``We're making immediate steps obviously. ``But we have to wait for the League's reaction.
``They will hopefully discuss it this evening and give us the go-ahead to make alternative arrangements regarding our pro situation.
``We owe it to our supporters to try to replace the pro and not work on a sub-pro basis all the time.
``We will endeavour, to the best of our ability, to get one to fill in and perform as well as Nathan and have the same attitude that he brought to the club.
``We wish him the best. He's an extremely nice guy and we didn't want to stand in the way of his ambitions or his career.''
Speaking today to the Lancashire Evening Telegraph, Astle emphasised his difficulty in making the decision to leave Thorneyholme Road after less than two months.
But he believes the move is in the best interests of his career.
``I'll be playing four-day games and one-dayers against quality players all the time - I had to take the opportunity,'' he said.
``It will be better cricket for me and I have to think about my future career.
``The people at Accrington looked after me really well and I'm sorry to be leaving them.
``But it's what I do as a job and I hope people understand.''