Debt holders appear to be pushing back against Pacific Capital Bancorp, the parent of Santa Barbara Bank & Trust in the middle of a $500 million rescue deal that requires debt holders’ cooperation.

Pacific Capital has more than doubled its cash offer on some of its outstanding debt and extended the deadline to accept to June 30. It did so after holders of just $50 million of the company’s $188.3 million in debt had agreed to terms that would have cashed them out at 20 cents to 30 cents on the dollar.

The new tender from Pacific Capital would give holders of its $67.3 million in trust preferred securities debt up to 40 cents on the dollar instead of 20 cents. The holders of Pacific Capital’s $121 million in subordinated debt would get up to 65 cents on the dollar instead of 30 cents.

Pacific Capital, by far the region’s largest independent banking company, is under pressure from federal regulators to boost its capital levels by Sept. 8 or potentially sell or liquidate the bank.

To avert disaster it has reached a deal with Texas-based Ford Financial Fund over a $500 million rescue. The deal would provide life-saving capital but would heavily dilute shareholders, leaving the Texas private equity firm with up to 91 percent of the company.

But the rescue needs the approval of bondholders as well as the U.S. Treasury, which must agree to take stock in exchange for one-fifth of its $180 million in bailout money and write off the rest. Common stockholders, who stand to be diluted heavily, also must agree.

With the specter of a bank failure or liquidation hovering in the background, the push to close Ford Financial’s rescue may come to resemble the rough-and-tumble negotiations most often reserved for reorganizations. Pacific Capital’s leaders have displayed confidence in their ability to persuade the various sides to cooperate.

“We wouldn’t have entered into an agreement like this we didn’t feel we had a strong chance of closing,” George Leis, CEO of Pacific Capital, told the Business Times in May.

Gerald Ford, the Texas banking veteran behind the rescue deal, has a history of passing on deals that didn’t meet his price. At the height of the banking crisis, he got special clearance from federal regulators to buy a troubled bank on his own. But since then, he shopped around for deals without closing one before approaching Pacific Capital.

“We’ve spent the last three years looking at banks all over the country. We’ve bid on them,” Ford told the Business Times in May.

Are you a subscriber? If not, sign up today for a four-week FREE trial orsubscribe and receive the Book of Lists free with your purchase.