East Lyme — Assistant Town Clerk Lesley A. Blais has been named the new town clerk.

Blais succeeds Esther B. Williams, who announced in December that she was retiring after 45 years in the town clerk’s office. Williams’ last day is April 5.

Blais has served for 20 years as East Lyme’s assistant town clerk, an appointed position. She will serve as town clerk until the next municipal election in November 2013, at which point she could run for the seat, First Selectman Paul Formica said.

“We are pleased that we have this type of stability to move into the town clerk’s position, as Lesley has shown an aptitude for service to the town clerk’s office and to the public at large over her ... two decades as assistant town clerk,” Formica said Wednesday. “We know Lesley will do a great job for the town and (we) look forward to her service.”

Blais will earn $59,000 a year in her new position, Formica said. He will recommend that the assistant town clerk’s hours be bumped up from part time, at 30 hours a week, to full time, at 37 hours.

The second assistant town clerk’s position will remain 25 hours a week, Formica said.