NEW YORK (Reuters) - Enbridge Energy Partners (>> Enbridge Energy Partners, L.P.) and the Enbridge Income Fund (>> Enbridge Income Fund Holdings Inc) said on Monday they had finished part of their Bakken crude pipeline expansion project, adding 145,000 barrels per day of capacity to the booming oil region around North Dakota.

Shale oil production from the expansive Bakken formation, which straddles the U.S. and Canadian border, has surged in recent years prompting a spate of infrastructure projects to help provide crude to refiners in the region and beyond.

In North Dakota alone, production has risen to almost 770,000 bpd at the end of last year from 100,000 bpd in 2006.

The Enbridge project, which entered service on schedule and under budget according to the company, reversed and expanded a pipeline running from Berthold, North Dakota, across the border to Steelman, Saskatchewan.

The companies also built a 16-inch (40-cm) pipeline from a new terminal in Steelman to Enbridge Pipelines Inc's mainline terminal close to Cromer, Manitoba.

"Once on the Enbridge mainline, Bakken production will have access to the multiple markets accessible from the mainline and connected pipeline systems," the two companies said in a statement.

"Firm commitments totaling 100,000 bpd have been received from anchor shippers," the statement said.

The project was the third expansion of Enbridge's transport infrastructure in the Bakken region in the past five years. Bakken production could rise to 1.2 million bpd in the coming years, the companies said.

Canadian pipeline operator Enbridge Inc (>> Enbridge Inc) has a 23 percent stake in Enbridge Energy Partners and a 20 percent stake in the Enbridge Income Fund.

(Reporting By Sabina Zawadzki; Editing by Marguerita Choy)