The pair will tie the knot June 16 at the ritzy Portofino resort on the Italian Riviera, The (London) Sun reported Tuesday. They will fly in their guests by private jet and then put them on a yacht after the ceremony.
Spending lavishly seems a contradiction for Stewart, the sexagenarian singer and father of seven who has earned a reputation for being stingy with tips while earning millions performing, the newspaper said.
"It is going to cost a small fortune but he wants it to be a memorable day," a Stewart confidante told the paper. "Some very famous names have been invited but they have been sworn to secrecy. It's going to be quite a day."
It's the third marriage for Stewart, who was wed to Alana Hamilton and Rachel Hunter, and the first for Lancaster. The couple has one child together.
2014: The Year in Music [PHOTOS]