Salix Pharmaceuticals is moving its headquarters back to North Raleigh.

The company said in a regulatory filing this week that it has signed an 11-year lease for 126,926 square feet of space at the Colonnade office park off Six Forks Road. The move is expected to happen this fall.

In 2005, Salix left the Colonnade for Duke Realty's Perimeter Park in Morrisville, where it had been leasing 77,000 square feet.

Salix had been subleasing its old corporate headquarters, about 26,000 square feet, in the Colonnade. That lease, which was set to expire in April, has been extended and Salix will eventually take over that space as well.

The total value of the two leases is about $36 million.

The move means Salix is executing a $1.7 million termination fee on its lease with Duke Realty in Perimeter Park.