FRANKFURT, April 29 (Reuters) - DaimlerChrysler AG posted first quarter operating profit of 1.541 billion euros ($1.82 billion) on Thursday, beating analysts expectations thanks to stronger earnings at Chrysler and trucks. Group sales fell three percent to 32.351 billion euros, while Chrysler's operating profit almost doubled to 298 million euros. Net profit came in at 393 million euros, the group said.