Robert Paul Properties opened the first of two new offices in Cambridge Wednesday, the company’s fourth Boston-area office in the past year.

Co-broker owners Robert Grover and Paul Kinlin have been well-known figures in the high-end market on the Cape for decades, founding and later selling brokerage Kinlin Grover before establishing Robert Paul Properties in Osterville in 2009. They opened their first Boston office on Newbury Street just last year, a rare move for a Cape-based brokerage.

"When we open the doors of our first of two Cambridge offices … it will mark the latest step in our mission to build a brokerage based on performance and experience in the luxury real estate market from Cape Cod and the South Coast to the South Shore and Boston area," the two wrote in a statement.

According to the firm, the recent expansion has helped fuel the brokerage sales volume to $540 million in 2014 from $411 million last year.