HOUSTON, May 20 (Reuters) - Crude oil tanker Dubai Angel

on Monday moored at the Westridge Marine Terminal in Vancouver,

preparing to load the first cargo of crude oil from the recently

expanded Trans Mountain pipeline (TMX), ship tracking data

showed.

Chartered by Canadian oil producer Suncor Energy ( SU ),

the Marshall Islands-flagged vessel was expected to load about

550,000 barrels of Access Western Blend (AWB) for delivery to

China, ship tracking data on Kpler showed.

Trans Mountain said it expects to load the first vessel with

oil from the expanded pipeline later this month.

TMX, which will ship an additional 590,000 barrels per day

(bpd) to Canada's Pacific coast from Alberta, began commercial

operations this month after years of regulatory delays and

construction setbacks.

Flows on the pipeline and loadings from the Westridge Marine

Terminal are being closely monitored by traders and shippers as

the expansion gives Canadian producers more access to U.S. West

Coast and Asian markets. Tightening supply of heavy crude has

made Canadian oil more attractive to buyers around the world.

However, logistical constraints at the Port of Vancouver

could limit the number of shipments, traders and shipping

sources have said.

The Port of Vancouver and Suncor did not immediately reply

to a requests for comments.

Suncor said this month that it was leasing Aframax vessels

in the Pacific and selling direct to customers, seeking to

maximize profits on oil being shipped on TMX.