Shares of AmeriGas Partners ( APU) advanced after the propane company said first-quarter earnings grew to $55 million, or 87 cents per limited partner unit, from $37.2 million, or 67 cents per unit, last year, excluding a one-time gain of $7.1 million.

Revenue for the quarter was $630.2 million, up from $556.2 million a year ago, the company said, principally reflecting higher propane product prices. AmeriGas Partners gained 28 cents, or 0.9%, to $30.49.

KFx ( KFX) slipped after the coal company agreed to acquire Buckeye Industrial Mining for $37.5 million. The company also said it planned to offer about 5 million shares. Part of the proceeds will be used to fund the Buckeye acquisition and plant-construction costs.

KFx gave the underwriters an option to purchase up to an additional 750,000 shares to cover overallotments. KFx fell $1.12, or 5.6%, to $18.97.

Defense contractor EDO gained after the company said it received a $30 million contract from Lockheed Martin ( LMT) for sonar equipment on the new Spanish S-80A submarine. The initial award covers outboard sonar arrays on four conventionally powered submarines, the company said. Shares of EDO advanced 48 cents, or 1.7%, to $28.11.

Shares of Tetra Tech ( TTEK - Get Report) were higher after the engineering company was awarded the rebid to its largest Federal Aviation Administration contract, the Global Positioning System Technical Assistance Contract 2.

The contract is worth about $60 million over two base years and one option year. Tetra Tech rose 72 cents, or 4.3%, to $17.38.