June 12 (Reuters) - Twenty-two oil tankers are scheduled

to load this month in Vancouver with crude from the expanded

Trans Mountain pipeline, which is running around 80% full with a

"little bit" of spot capacity also being used, a Trans Mountain

executive said on Wednesday.

Speaking with Reuters six weeks after the C$34.2 billion

($24.94 billion) project started commercial operations, Trans

Mountain Corp's chief financial and strategy officer Mark Maki

said so far the system is operating as expected and final costs

for the expansion are not expected to rise significantly.

The Trans Mountain expansion, which tripled pipeline

capacity from Alberta to Canada's Pacific Coast to 890,000

barrels per day (bpd) started commercial operations on May 1 and

traders are closely watching flows to gauge demand.

Eighty percent, or 707,000 bpd, of the pipeline's capacity

is reserved for long-term contracted shippers, while the

remaining 20% is available to spot barrels.

"We're basically running at effectively right around

contract level with a little bit of spot on the system," Maki

said, adding that volumes were expected to rise towards winter.

Maki said there were 22 tankers scheduled to load at

Westridge dock, the pipeline's terminus in the Port of

Vancouver, in June.

Traders and shipping sources had been concerned that

logistical constraints at the port could limit tanker loadings

at Westridge to less than 20 a month.

So far the marine facility is performing well, Maki added,

although the company had to work through some start-up issues on

one piece of equipment known as a vapor recovery unit, which

removes unwanted vapors from crude.

"The dock facility is working as we'd expected. There are a

few things of course you've got to break in and get running

right, but we're happy with where we're at," Maki said.

The pipeline is owned by the Canadian government, which has

been criticized for the cost of the expansion ballooning to

nearly five times its 2017 budget estimate.

Maki said post-construction remediation work is still

ongoing but Trans Mountain Corp would have a final cost in place

by the end of this year and it would likely be "very, very

close" to C$34 billion dollars.

He also said it was unlikely Trans Mountain would need to

further increase a C$19 billion loan facility agreed with a

syndicate of commercial banks and guaranteed by the Canadian

government, unless it was for a transitory purpose like issuing

bonds.

"If we do it would probably be transitory and not a

particularly large increase," Maki said.