The three brands of Royal Caribbean Cruises Ltd. have raised sales commission thresholds for 2009, the first time the company has done so since 1999.

Vicki Freed, Royal Caribbean International’s senior vice president of sales and marketing, said, for example, that in order to maintain a 16% commission level, an unaffiliated agency’s revenue would have to jump from $1.1 million to $1.5 million in sales for Azamara, Celebrity and Royal Caribbean.

“While the jump sounds high, the reality is that only 472 agencies currently at 16% are potentially in jeopardy of dropping from 16%,” Freed said. “We plan on aggressively working with these agents and any other agent that may want to maintain or increase their base commission.”

The change was first reported by industry newsletter Cruise Week, which said an agent’s sales at the end of the year would set its 2009 commission levels for bookings.

Freed said that the increase recognizes that 17 additional ships have been added to the RCCL fleet since 1999, the last time the company increased its base commission thresholds.