Shares of ExpressJet Holdings surged 41 percent Monday, boosted by the announcement of a new partnership with United Airlines.

United said in a statement that ExpressJet will operate 22 ERJ-145 aircraft under the United Express banner. The flying will begin May 2010 and will replace work previously done by other carriers.

ExpressJet shares closed up over 41 percent, or $1.05, at USD$3.61. The company's stock was the top percentage gainer on the New York Stock Exchange.

The Arca Airline Index was up 2.3 percent.

ExpressJet shares have jumped more than 90 percent so far in 2009, after a 93 percent tumble in 2008.