Canada could end up more of a buyer than a seller of clean technology without more support from the federal government, a B.C.-based group of investors and entrepreneurs says.

The BC Cleantech CEO Alliance has sent a letter to Prime Minister Justin Trudeau, stressing the need for the government to do more to develop the sector.

Globally, spending in the industry has grown to $1 trillion annually in the past 10 years.

Over the same period, the alliance says, Canada's clean-tech sector has also expanded, and its exports are comparable to those of forestry, livestock and mining.

Clean technology is "unequivocally a pillar of the Canadian economy," the group says. However, Canada's share has been eroded, it warns.

"In fact, Canada has been the world's third greatest loser of market share for clean-tech solutions since 2008, [with its global ranking] falling from 14th to 19th in terms of total market share as other countries pour investment dollars into pioneering these technologies," the letter says.

Canada, it says, is losing global market share to increasing competition from the United States, China, Germany, Singapore, Israel and other jurisdictions.

In its letter, the BC Cleantech CEO Alliance offers the following recommendations:

Create a federal clean-tech task force by the end of June, made up of clean-tech leaders and government, to design a national strategy for clean-tech investment and development.

Allocate $500 million to establish Canada as a powerhouse of clean-tech venture capital.

Introduce the same tax credits for clean-tech companies as those in the mining and oil and gas industries to free up investment dollars.

Make greater financing available, namely loan guarantees such as those developed by the U.S. department of energy or the Swiss government, and have the private sector manage the program.

Expand the Sustainable Development Technology Canada fund, backing biofuel, to include support for all types of clean technologies.

Last May, a report by Analytica Advisors also said Canada's clean-tech sector has been growing, but it's falling behind globally.

It said exports grew to $12 billion in 2013, but Canada's share of the global market has declined 41 per cent since 2005.

China's share of the market was the largest, at 20 per cent, according to the report by the Ottawa-based company, which monitors and reports on Canada's expanding clean-technology sector.