The British Darts Organisation will change its rules to allow Professional Darts Corporation players to take part in its competitions.
BDO members can also play in the PDC's Qualifying School when the new rules take effect from 1 October.
Female players will be able to enter PDC World Championship qualifying.
BDO players had faced penalties if they took part in PDC events, and those who reached the BDO world semi-finals were obliged to remain within its system.
BDO world champion Glen Durrant appeared to welcome the move on Twitter, posting a picture of himself next to a PDC Qualifying School graphic.
The BDO World Championship, established in 1978, was for years dart's most prized trophy before the PDC emerged.
Initially formed as the World Darts Council in January 1992, the PDC is now the leading professional body in darts.
A BDO statement said the rule changes showed its "intent to overhaul the current system and make positive changes for the better from within the organisation".