UPDATE 2-Atlantic Coast Federal names Jay Sidhu as exec chairman

* Names ex-CEO of Sovereign Bank as exec. chairman

* Sidhu currently runs Customers 1st Bank

* Succeeds former Chairman Charles Martin

* Shares rise as much as 24 pct (Adds details, background about Sidhu, updates share movement)

May 27 (Reuters) - Bank holding company Atlantic Coast Federal Corp (ACFC.O) named Jay Sidhu, who built Sovereign Bancorp Inc into the second-largest U.S. savings and loan, as its executive chairman, and its shares rose about 24 percent.

Sidhu ran Sovereign from 1989 to 2006, and left under pressure amid criticism over the Philadelphia-based thrift's stagnant share price and its agreement to sell a nearly 25 percent stake to Spain's Banco Santander SA (SAN.MC). Santander bought the rest of Sovereign in January 2009.

Sidhu, who runs Sidhu Advisors, a private equity and financial services consulting company, said he would focus on strengthening the capital position of Atlantic Coast.

"Since joining our board in March, Jay has energized our efforts to attract new capital and explore strategic opportunities," Atlantic Coast Chief Executive Robert Larison said.

Sidhu succeeds Atlantic Coast's former Chairman Charles Martin.

Sidhu, who is the CEO of Customers 1st Bank NCYB.PK, formerly known as New Century Bank, was raising $43.1 million in capital for the Phoenixville, Pennsylvania-based bank, a source familiar with the plan had said in February. [ID:nN17131564]

The idea was to buy failed banks from the Federal Deposit Insurance Corp to build a dominant community bank focused on the mid-Atlantic region, the source had said.

Shares of Waycross, Georgia-based Atlantic Coast were up 20 percent at $3.00 Thursday morning on Nasdaq. They touched a high of $3.09 earlier in the day.

(Reporting by Abhinav Sharma in Bangalore; Editing by Aradhana Aravindan)