* C$400 million Kirby project

* Latest in string of plans deferred or canceled

* Units up 1.8 percent at C$23.53 (Adds details)

CALGARY, Alberta, April 17 (Reuters) - Enerplus Resources Fund (ERF_u.TO: Quote, Profile, Research) said on Friday it is shelving its C$400 million ($330 million) Kirby oil sands project in Alberta, joining a long list of companies that have deferred such developments due to low oil prices and shaky credit markets.

Enerplus sold its stake in a much larger oil sands project last year so it could focus on Kirby. It filed regulatory applications last September for a 10,000 barrel a day first phase.

"While we believe there is long-term value in the Kirby project, the current cost structures, commodity price environment and our cost of capital do not offer a sufficient economic return for additional investment toward project sanctioning at this time," it said in a statement.

The company owns 100 percent of the project, where plans called for steam to be pumped into the ground to loosen up the tar-like bitumen so it can be pumped to the surface in wells. The method is called steam-assisted gravity drainage.

Kirby's current resource estimate is more than 400 million barrels. Enerplus had envisioned producing 40,000 barrels a day by 2017, with the first phase producing by 2012.

Since weak oil prices took hold last September, companies have deferred or canceled more than C$90 billion worth of oil sands projects. The oil sands are far more expensive to develop than traditional oil and gas fields.