* BlackRock, Canada Pension Plan back convertible note

* Omers, IMCO also help lead latest funding round

* Close to agreeing plan for Canadian factory - sources

STOCKHOLM/LONDON, Aug 22 (Reuters) - Swedish lithium-ion battery producer Northvolt has raised $1.2 billion from investors including BlackRock and several Canadian pension plans as it prepares to build new factories in Europe and North America, its finance chief told Reuters.

The fresh funding, through a convertible note, comes as investor demand for companies set to benefit from the move to a low-carbon economy picks up pace, aided by policy initiatives in both regions to accelerate the transition.

"It's a very capital intensive industry... finding the right mix is always hard in this new greenfield kind of transitional projects," Chief Financial Officer Alexander Hartman said in an interview.

Leading the round alongside BlackRock, the world's biggest asset manager, were Canada Pension Plan, Ontario Municipal Employees Retirement System and, as previously reported, pension investor Investment Management Corporation of Ontario.

Other investors to take part included Goldman Sachs, Volkswagen, Baillie Gifford, Swedbank Robur , Singapore's GIC and Hong Kong-based Chow Tai Fook Enterprises.

A number of funds to invest in the note were classed as 'dark green' under the European Union's sustainable finance framework, a stamp of environmental approval that bodes well for future interest in the company, which ultimately hopes to list, Hartman said.

The fresh funds will help the firm expand its factory footprint, Hartman said. The firm currently has several factories across Europe with the latest a 600 million euros ($654 million) investment to build a plant in Germany, announced in May.

While the company has a facility in the United States, sources said the company is close to finalising plans to build a multibillion-dollar battery factory in Canada that will be announced later this year.

Northvolt declined to comment on the factory plans.

With the latest round, Northvolt has raised more than $9 billion in debt and equity since 2017 in its bid to become Europe's biggest battery manufacturer, including $1.1 billion in convertible notes last year from multiple investors.

It has secured orders of over $55 billion from customers such as BMW, Fluence, Scania, Volvo Cars and Volkswagen.

Separately, Northvolt has assembled its first energy storage system products in Poland and expects to start customer deliveries from later this year.

"We have a business plan... we always want to make sure we have access to the markets," Hartman said.

He declined to comment on whether the company was preparing to go public.

Reuters has previously reported, citing sources, that Northvolt was preparing for an initial public offering that could value the company at more than $20 billion.

($1 = 0.9176 euros) (Reporting by Supantha Mukherjee in Stockholm and Simon Jessop in London Editing by Mark Potter)