Cadence Financial (NASDAQ:CADE) surged more than 18% Wednesday after the bank said it has terminated its previously announced agreement with Trustmark (NASDAQ:TRMK) and will now be acquired for $30 million by Community Bancorp at what it called a higher and more certain price.

Trademark had only offered to buy the Houston-based bank holding company for $23.6 million in stock.

Community Bancorp, a limited liability company created with the specific purpose of investing in community banks, has agreed to acquire Cadence through the merger of the bank with one of its newly formed subsidiaries, with Cadence being the surviving corporation.

Under the terms of the deal, Community Bancorp shareholders will receive $2.50 a share in cash per one Cadence share, reflecting a 20% premium to Cadence’s closing price Tuesday of $2.08.

It has additionally offered to buy the $44 million of its preferred stock and the associated US government warrant issued to the US Department of Treasury under the government’s bailout program for $38 million in cash.

The Treasury has indicated its willingness to sell its Cadence preferred stock and warrant for the cash consideration subject to definitive documentation acceptable to the Treasury’s discretion.

Cadence CEO Lewis F. Mallory Jr. said the offer will deliver “more value” to the company’s shareholders, as it represents a “higher, more certain price” than the previous offer.

The transaction, subject to customary closing conditions, is expected to close by the first-quarter of 2011.