Avangrid has $30 billion worth of assets, according to Iberdrola, following the merger with the US utility.
The company will own Iberdrola's US wind operating portfolio of approximately 5.6GW of wind energy across 53 projects. The pipeline stands at approximately 5.9GW. The company is the second largest wind energy producer, according to Iberdrola.
Avangrid will also cover Iberdrola's USA Networks arm, which owns and operates natural gas and electric utilities in the northeast US, and Iberdrola Energy Holdings - a natural gas storage and energy services company based in Houston, Texas.
Avangrid's management team will be headed by CEO James P Torgerson, the former CEO of UIL Holdings Corporation.
Iberdrola's chairman, Ignacio Galan said: "As we have done since our arrival in the United States in 2006, we will continue investing in clean energy across the country, and bring new value to our utility customers through improving infrastructure, new technology, and innovative services."
Avangrid began trading on the New York stock exchange on 17 December, opening at $38.75 but falling to $36.12 overnight.
UIL was owner of a number of electric and natural gas utilties across the US.