The football teams from Cal Poly and UC Davis are joining the Big Sky Conference, league commissioner Doug Fullerton said Tuesday.

The universities accepted the invitations to join the conference as football-only schools late last week after university presidents approved a change to league rules that require all member schools to take part in the same 14 sports.

Cal Poly and UC Davis are Football Championship Subdivision members that compete in the Great West Conference but participate in the Big West Conference for the majority of their sports.

A timeline for the move has not been set.

"Our obligation and commitment to them is to work them in just as quickly as we can," Fullerton said.

Many of the Big Sky Conference teams have their 2011 schedules nearly complete and Cal Poly and UC Davis must officially withdraw from the Great West Conference, which also includes football teams from North Dakota, South Dakota and Southern Utah.

Fullerton said he expects Cal Poly and UC Davis to end up with some games against Big Sky schools next year, a heavy slate of games in 2012 and a likely full schedule by 2013.

The nine full-time Big Sky Conference members are: Eastern Washington, Idaho State, Montana, Montana State, Northern Arizona, Northern Colorado, Portland State, Sacramento State and Weber State.

"The Big Sky is recognized as one of the top Football Championship Subdivision conferences in the nation," Fullerton said in a statement. "The addition of two great institutions like Cal Poly and UC Davis gives us more depth to compete for additional playoff berths and enhances our profile throughout California.

"They will benefit from us in having access to an automatic playoff bid and a full slate of conference games," he added.

UC Davis football coach Bob Biggs has a 12-8 record against Big Sky teams over the past 17 years.

"We've played at least three Big Sky opponents every year since 2004 and look forward to strengthening those existing rivalries while building exciting new ones that fans will identify with," Biggs said in a statement. The Aggies host Portland State on Saturday.

Cal Poly head coach Tim Walsh coached Portland State from 1993-2006, including the team's transition into the Big Sky in 1996. The Mustangs host top-ranked Montana on Saturday night.

The athletic directors at both schools said they are happy with the upcoming move.

"Our goal all along has been to find stability for our football program, and the Big Sky Conference gives us exactly what we needed," said Cal Poly athletic director Alison Cone.

UC Davis athletic director Greg Warzecka called the move exciting.

"Our fans will not only be able to watch some great teams come to Aggie Stadium, but they will have a much better opportunity to travel to road games," he said in a statement released by the Big Sky.

Tuesday's moves are the first part of an expansion that could lead to a 12-team Big Sky football conference with two six-team divisions, Fullerton said.