The Orioles and Nick Markakis engaged in negotiations for a contract extension in the past week, but those discussions halted yesterday and likely will not be rekindled until after the season, several baseball sources said. Markakis, 24, who is considered the cornerstone of the team's rebuilding plan, is eligible for arbitration after the season and is under the Orioles' contractual control through the 2011 season. Asked about the talks between the Orioles and Jamie Murphy, Markakis' agent, club president Andy MacPhail said: "We don't comment on negotiations."