A 45-year-old woman and an ex-company director were each jailed for four years yesterday for trying to arrange a sex session with teenage girls.

Vanessa Jones, from Birmingham, and Michael Chester, from Grimsby, pleaded guilty to attempting to arrange the commission of a child for a sexual offence in what is believed to be the first prosecution of its kind in the West Midlands.

Jones, a single woman with a teenage son, and Chester (42) a married father-of-two at the time the offences were committed, met in an internet chatroom.

They were members of a website for swingers and messaged each other regularly about their desire to have sex with children. They met in person several times.

The plan to drive to Leeds and meet another couple who would provide two teenage girls, age 14 and 16, for their sexual gratification came about after another person registered with a website.

This man, who eventually reported Jones and Chester to police, told the pair neither he nor his partner were interested in the proposal and contacted the NSPCC with his concerns.

Jones and Chester were arrested in April 2005 in connection with offences dating back to November 2004.

Computer equipment containing indecent images of children was seized from both their homes. Sentencing the pair at Birmingham Crown Court, Judge Michael Challinor told them their behaviour encouraged others to abuse children in unspeakable ways.

He said: "The aggravating feature of this case is the use of the internet to make contact with like-minded individuals who you hoped would deliver children into your hands in order that you could abuse them sexually.

"What must be remembered is that the internet is a powerful method of communication and if misused it can seriously endanger the safety of children.

"People who misuse the internet in the way you did must, if detected, expect a severe sentence.

"My sentence must be imposed in order to punish you, to protect others from you but principally to deter others who might be tempted to behave in this way."

The pair were told to register as sex offenders indefinitely.