Arriva Trains Wales says a strike, due to hit services in North Wales, has been called off.
Members of the RMT union, at three depots including Holyhead and Llandudno Junction, were due to walk out tomorrow and Friday.
Talks will resume to resolve the dispute.
Flooding means there are no trains running between Blaenau Ffestiniog and North Llanrwst. There are replacement buses.
There are delays of up to 15 minutes on Arriva Trains Wales between Treherbert and Cardiff Central, between Aberdare and Cardiff Central and between Merthyr Tydfil and Cardiff Central because of over running engineering works at Pontypridd.
Network Rail says there was a derailment in the early hours of this morning at Porthkerry in the Vale of Glamorgan.
Two wagons of a freight train came off the rails and accident investigators are at the scene.
Nobody was hurt but services between Bridgend and Barry have been suspended. A bus service has been introduced.
There is no word yet on when train services will resume.
There's a replacement bus service running on Arriva Trains Wales between Barry and Bridgend because of a derailed train at Barry.
Trains cannot run so buses will operate in both directions, extending journey times by up to 30 minutes.
There's disruption on Arriva Trains Wales services between Pontypridd and Aberdare and between Pontypridd and Merthyr Tydfil.
It's because of a signalling problem between Pontypridd and Abercynon.
An hourly service is running instead of a half hourly one, and cancelled trains are being replaced by buses.
Services that do run may be delayed by up to 15 minutes. Arriva Trains Wales expect normal service to resume at around 12:00
There are delays of up to 30 minutes on Arriva Trains Wales between Cardiff Central and Treherbert, between Barry Island and Aberdare and between Penarth and Rhymney because of a signalling problem at Cardiff Central.
There are delays of up to 45 minutes on Arriva Trains Wales between Newport and Hereford because of a signalling problem between Pontypool and New Inn and Abergavenny.
There's disruption on Arriva Trains Wales between Cardiff Central and Merthyr Tydfil, between Cardiff Central and Aberdare and between Cardiff Central and Ebbw Vale Parkway because of over-running engineering work between Cardiff Central and Rhoose Cardiff International Airport.