BOK Financial in Tulsa, Okla., has agreed to buy CoBiz Financial in Denver.

The $33 billion-asset BOK Financial said in a press release Monday that it will pay $977 million in cash and stock for the $3.8 billion-asset CoBiz. The deal, which is expected to close in the fourth quarter, prices CoBiz at 290% of its tangible book value.

The deal is one of the biggest bank mergers announced this year and comes just weeks after Guaranty Bancorp in Denver agreed to sell itself to Independent Bank Group in McKinney, Texas, for $1 billion.

CoBiz is a commercially focused bank with operations in Colorado and Arizona. The company specializes in health care and public finance.

Steve Bangert, CoBiz’s chairman and CEO, will become Colorado vice chairman for BOK Financial's bank. He will also join BOK Financial’s board.

“CoBiz is a perfect fit as a merger partner,” Steven Bradshaw, BOK Financial’s president and CEO, said in the release. BOK Financial and CoBiz “have enjoyed a close relationship for almost two decades, and both franchises will benefit as a result of this partnership.”

BOK Financial said it expects to incur pretax merger and integration costs of about $61 million. It plans to cut about 40% of CoBiz’s annual noninterest expense.

The deal is expected to be 6% accretive to BOK Financial’s 2019 earnings and 9% accretive to next year. It should take about six years to earn back the deal's nearly 9% dilution to BOK Financial's tangible book value.

Goldman Sachs and Frederic Dorwart, Lawyers advised BOK Financial. BofA Merrill Lynch and Simpson Thacher & Bartlett advised CoBiz.