TransCanada Corp (TRP.TO) has agreed to sell its solar energy portfolio for $540 million (US$426 million) to focus on its $24 billion worth of other core projects, including its recently purchased Columbia natural gas network, the company said on Wednesday.

TransCanada's solar portfolio, based in Canada's Ontario province, comprises eight facilities with a generating capacity of 76 megawatts.

"This transaction demonstrates our financial discipline as we continue to build on our vision of being North America's leading energy infrastructure company," said TransCanada CEO Russ Girling in a press release. 

TransCanada had bought the solar assets for $470 million between 2013 and 2014, according to the company.

Royal Bank of Canada analyst Robert Kwan said the sale of non-core assets is an efficient way to raise money and was a "slight positive" for TransCanada, even though the size of the sale was small.

Pipeline companies have been under pressure after consolidating to shed non-core assets as they grappled with overcapacity and sliding tariffs that had slowed dividend growth and unnerved investors.

It is uncommon for pipeline companies to be heavily involved in solar, and TransCanada's sale to focus on its main business makes sense for the company, said Altacorp analyst Dirk Lever.

The asset was bought by privately held Axium Infrastructure Canada II Limited Partnership, a Montreal-based private equity firm.

TransCanada's solar portfolio, based in Canada's Ontario province, comprises eight facilities with a generating capacity of 76 megawatts.

Royal Bank of Canada analyst Robert Kwan said the sale of non-core assets is an efficient way to raise money and was a "slight positive" for TransCanada, even though the size of the sale was small.

The Calgary, Alberta-based TransCanada, which operates the Keystone pipeline, said proceeds from the sale would help fund its $24 billion near-term capital program.

TransCanada, the country's No 2 pipeline operator, sold other assets and offered new shares late last year and stakes in two U.S. natural gas pipelines this year to fund the same program.

The program includes TransCanada's US$10.3 billion acquisition of the Columbia Pipeline Group, a deal that eased concerns over its outlook, which had been hindered by challenges on crude pipelines.

TransCanada rival Enbridge last year sold more than $1 billion in non-core assets after it bought the U.S.-based Spectra Energy, a move that created North America's largest pipeline operator.