A French side will be invited to join National League One from either 2009 or 2010 onwards.
The Rugby Football League has asked the French Rugby League Federation to propose a club before 30 September.
Toulouse, who missed out on a Super League licence this week, are likely to be the favourites to be nominated.
The RFL are also investigating opportunities for other European clubs, possibly from Scotland or Ireland, to participate in the competition.
RFL chief executive Nigel Wood said: "We believe the inclusion of a French club in Co-operative National League One would add tremendous value and interest to the competition.
"It would give the League a broader appeal, offer all supporters an exciting new element to their viewing experience, create added interest for broadcast partners and continue to drive up playing standards at this level of the sport."
On Tuesday, the RFL confirmed that only one team will be relegated from National League One this season, with three coming up from League Two.
The top two in National League Two will go up automatically, with the third team progressing via the play-offs.
The addition of a French side would make it an 11-team league with 10 clubs in League Two.
Under proposals being considered, the National League could also stage its own "Magic" Weekend and adopt the Super League's licensing system.
Unlike Super League though, promotion and relegation will be retained.
Wood added: "Clubs have expressed an interest for a similar style for the National League and we are looking into this."
"It's encouraging that clubs are considering a form of licensing that will help improve standards.
"Following the success of the Magic weekend, clubs have expressed an interest for a similar style event for the National Leagues and this is something we are looking into developing."
