Hard economic times have prompted an organization that bargains for Alberta's unionized building trades to sign a deal that includes lower pay for some workers in the hope of keeping them on the job.

The agreement that is to start Jan. 1 covers employees who do daily upkeep and prepare for shutdowns and overhauls at oilsands, energy, petrochemical and other industrial plants

Brett McKenzie, executive director of the General Presidents' Maintenance Committee, said union members are to be paid 75 cents an hour less than if they were doing construction work. There are also some changes to overtime and benefits.

The three-year deal aims to help contractors, who employ union members, to win maintenance contracts as industrial construction activity in Alberta winds down.

"These concessions are necessary to keep us in the game, to keep us on the inside of the fence," said McKenzie.

"If our contractors are not in a position to win contracts, we are not going to be in a position to provide jobs and opportunities for the members of the local unions in Alberta."

The agreement covers carpenters, electricians, ironworkers, labourers, millwrights, operating engineers, pipefitters, sheet-metal workers and other trades.

There is no ratification vote.

In recent years, maintenance work has amounted to the equivalent of about 10,000 full-time jobs, McKenzie said.

He lays out the need for change in open letters to union members about how low oil prices and the downturn in the energy sector have already cost tens of thousands of Albertans their jobs.

Union members are being told there will be fierce competition from non-union firms and the Christian Labour Association of Canada over the next few years for maintenance work.

The message is that if the building trades cannot meet new market demands, someone else will.

"Alberta has gone from a province that once had seven multibillion-dollar construction projects going on all at once to a province that only has two," McKenzie said in an interview.

"There is a supply of skilled labour out there and there are an enormous amount of contractors competing for the maintenance work."

Warren Fraleigh, executive director of the Building Trades of Alberta, said it is challenging to communicate reasons for lower pay to union members who have worked in the oilpatch for years, including during boom times.

Fraleigh said there have already been significant layoffs of workers in some trades, such as operating engineers, due to the downturn in construction.

The situation is expected to get worse, he said.

"Our members may be working today. There is a lot of indicators that are telling us right now that that is not going to be in the case six to 12 months from now."

Fraleigh said there will be more people looking to be hired for maintenance contracts once construction work dries up

Building Trades of Alberta represents unions with members who work in the construction, maintenance and fabrication industries.