Virgin Group founder Sir Richard Branson today announced that Virgin Atlantic Airways, Virgin America and V Australia/Virgin Blue are teaming up to offer each airline's loyalty program members the opportunity to earn miles or points when taking flights on their sister-branded airlines.

As of today, guests flying on all Virgin airlines are eligible to earn miles or points for their flights that can later be redeemed under any of the carrier's frequent flyer programs, the company said.

The reciprocal agreements enable Virgin Atlantic's Flying Club members to earn Flying Club miles/status points, Virgin America's Elevate members to earn Elevate points, and V Australia/Virgin Blue Velocity members to earn Velocity points wherever they are flying on a Virgin-branded carrier around the world.

Virgin Atlantic Flying Club members and V Australia/Virgin Blue Velocity members can also redeem their miles on either of the airlines. V Australia/Virgin Blue Velocity members and Virgin America Elevate members will be eligible to use their miles or points to fly on either airline as of the fourth quarter of 2010.

Virgin Atlantic Flying Club members and Virgin America Elevate members will be eligible to spend their miles or points on either airline as of the second quarter of 2011.

To celebrate this Virgin milestone, each Virgin airline is offering members who fly with at least two of the four Virgin branded airlines between now and January 31, 2011 the chance to win a week holiday in the British Virgin Islands on Sir Richard Branson's private island Necker.

Virgin America and Virgin Atlantic also announced today that they will offer seamless travel on the networks of each carrier via an international one-way interline agreement for bookings and travel starting September 2010.

Virgin America launched a US-Australia interline arrangement with V Australia/Virgin Blue in June 2009. Virgin Atlantic and V Australia/Virgin Blue also have an interline agreement in place.