Peter M. Ill, a longtime Dominion Enterprises executive described by the company’s president as “the father of our Internet efforts,” will leave the company in May.

Ill, who was in charge of Dominion’s Internet business from 1997 through 2004, is credited with developing the company’s Internet portals for homes, apartments, employment and autos.

Under his leadership, Dominion’s electronic media division grew revenue from $1.1 million to $74.7 million and its staff from 17 to 763, said Dominion Enterprises President and Chief Operating Officer Jack Ross in a memo announcing Ill’s departure.

Ill helped the company acquire a number of other businesses, including Homes.com, eProspecting, eNeighborhoods and 123Movers.com.

He was named president of Dominion Homes Media in 2007, with responsibility for Harmon Homes, Homes.com, Agent Advantage, Advanced Access, Best Image Marketing and eNeighborhoods. All told, Ill was with Dominion Enterprises and its predecessors for 23 years.

“Peter has made many significant contributions to our company, including helping key Dominion Enterprises’ successful migration from print to Internet,” Ross said in the memo. “He will be remembered for his high energy, intelligence, eagerness, versatility and positive way with his people.”

In a statement, Ill said “it’s a good time to depart, knowing that the strength of our team and its leadership will drive success … for years to come.”

The company’s remaining managers include Jason Doyle, Andy Woolley and Lawrence Schoeffler, and Ill noted that the company plans to introduce new products in coming months.

According to the latest numbers from Web metrics firm Experian Hitwise, Homes.com was the eighth most popular real estate portal in February, and ForRent.com, another Dominion portal, ranked 15th.