Chelsea FC Sack Manager Andre Villas-Boas

Chelsea manager Andre Villas-Boas has "parted company" with the Premier League club after less than a season in charge, the west London side has announced.

The 34-year-old lost his job following Saturday's 1-0 league defeat to West Brom, which left the Blues fifth in the table and out of the lucrative Champions League qualification places.

A woeful run of results - including just one win in their last seven matches and only three from their last 12 in the league - forced Russian billionaire owner Roman Abramovich to act.

Villas-Boas , who was appointed last June, also had strained relationships with several of Chelsea 's senior stars, including England midfielder Frank Lampard .

The Blues announced assistant manager Roberto Di Matteo, a former Chelsea player and West Brom manager, would take charge of the team until the end of the season.

Portuguese Villas-Boas was only appointed eight months ago and cost Abramovich £13.3m to land from Porto.

He was the seventh manager to leave Stamford Bridge since the Russian bought the London club in 2003.

Chelsea said in a statement on their official website: "Andre Villas-Boas has parted company with Chelsea Football Club today.

"The board would like to record our gratitude for his work and express our disappointment that the relationship has ended so early.

"Unfortunately the results and performances of the team have not been good enough and were showing no signs of improving at a key time in the season.

It added: "The club is still competing in the latter stages of the UEFA Champions League and the FA Cup, as well as challenging for a top-four spot in the Premier League, and we aim to remain as competitive as possible on all fronts.

"With that in mind, we felt our only option was to make a change at this time.

"With immediate effect, Roberto Di Matteo has been appointed first-team coach on an interim basis until the end of the season."

Having repeatedly insisted he had Abramovich's full backing, Villas-Boas appeared to acknowledge the writing was on the wall recently.

In an interview with a Portuguese radio station he admitted he could lose his job if Abramovich followed his pattern of axing previous under-achieving managers.

And after Saturday's loss at West Brom, he said: "Will this result increase pressure on me? You have to agree with it. We are in the same position, fifth, but we are now three points behind Arsenal.

"It is a big, big disappointment. Every defeat Chelsea suffers piles more pressure on any manager."

Villas-Boas has been in football management for less than three years but was hired by Chelsea after winning four trophies at Porto last season.

He has been under constant pressure since replacing Carlo Ancelotti, who was fired after failing to win a trophy last season despite a league and FA Cup double the previous year.

That change of mangers cost Chelsea £28m in compensation.

Di Matteo's first game in charge will be Tuesday night's FA Cup fifth-round replay at Birmingham.