PORTLAND — Magellan Petroleum Corp., a gas and oil exploration company, named a new CEO today and said it plans to move its headquarters to Denver.

William H. Hastings resigned as CEO and president of Magellan after the board approved the relocation. He will remain a board member and become a senior adviser on growth ventures and business development, Magellan said.

The board appointed J. Thomas Wilson, a consultant for Magellan, as the new CEO and president. Wilson will continue as a company director.

Shares of the Portland company fell 6 cents, or 4.5 percent, to end at $1.26 per share.