Is it okay to send a query letter to a different literary agent in the same company?

I've only seen it listed a couple of times in an agency's submission guidelines that once you're rejected by one agent, you're to consider it a rejection by the entire agency for the same work. Likewise, I've read only a couple of times where it's stated that it IS okay to query another agent for the same work if the first agent you queried doesn't feel it's right for him/her. All the other agencies I've researched don't say anything one way or the other. So if an agency has several agents that represent the kind of work you're writing, is it generally acceptable to query a different agent in their company for the same book, if you've been rejected already? (Not at the same time, of course, I do know that much. LOL)