WASHINGTON — Washington Gas parent company WGL Holdings will officially be owned by a Canadian company as of July 6, after the two firms agreed to final terms of their merger as spelled out by D.C. regulators.

The D.C. Public Service Commission signed off on the $6.4 billion acquisition last week.

WGL Holdings and Canadian utility AltaGas had five days to accept its conditions that, among other things, addressed cybersecurity, environmental, safety and reliability concerns.

Washington Gas customers will also get a one-time rate credit, and the newly formed utility will help fund District workforce development initiatives.

Approval from Maryland regulators was granted in April and includes credits for residential customers, as well as workforce development and energy efficiency programs.

Overall, AltaGas will provide more than $138 million in customer benefits across D.C., Maryland and Virginia, the company said in a statement.

“This merger brings together two complementary energy companies that will deliver more value for customers by providing a variety of energy products and services and investing in the communities we serve,” said Terry McCallister, chairman and CEO of WGL Holdings, Inc., the parent company of Washington Gas.

WGL will continue to operate as a stand-alone utility and keep its D.C. headquarters.

The company has about 1,500 employees in D.C. and 1.1 million customers in the D.C. area.

AltaGas will also move the headquarters of its U.S. power business to the District, bringing about 20 jobs initially.