Shares of Enterra Energy Trust ( ENT) were among the NYSE's losers Tuesday, tumbling 11% after the oil and gas income trust slashed its target payout ratio. The company's new target payout ratio will range from 60% to 70% of cash flow from operations, down from a previous target range of 90% to 100%. Production volumes, the company said, remain on target and development project results remain positive. "Lowering the distribution payout increases flexibility and ensures cash is available to exploit Enterra's inventory of drilling and development opportunities for the long-term sustainability and growth of Enterra," the company said. As a result of the reduced payout ratio, the company revised its July cash distribution to 12 cents per unit, down from 18 cents per unit. Shares were trading down $1.55 to $12.01. Pep Boys ( PBY) rose 5% after the auto-parts retailer said Chief Executive Larry Stevenson resigned, effective immediately. Stevenson will be replaced, on an interim basis, by non-executive Chairman Bill Leonard. Pep Boys said that it is conducting a search to find a full-time replacement. Shares were trading up 54 cents to $11.91. Shares of Target ( TGT) slid 5% after the retailer lowered its July same-store sales forecast. The company now sees same-store sales growth of 3% to 4%, down from an earlier forecast of 4% to 6%. During the year-earlier period, the company posted a same-store sales increase of 5.5%. Shares were down $2.55 to $45. Shares of BlackRock ( BLK) dropped 5% after the asset manager posted solid second-quarter earnings but gave a soft forecast for 2007. The company earned $63.4 million, or 95 cents a share, up from $53.3 million, or 80 cents a share, a year earlier. Excluding charges related to the company's pending purchase of Merrill Lynch's ( MER) investment management business and other costs, adjusted earnings were $1.19 a share. Analysts expected earnings of $1.17 a share, before items. Assets under management totaled $464.07 billion at June 30, up from $414.41 billion a year earlier and $463.06 billion at March 31.