LONDON -- Celebrity chef Jamie Oliver's British restaurant chain filed for bankruptcy protection on Tuesday, partly due to increased competition and escalating rents in local commercial districts.

The insolvency put 1,300 jobs at risk and reignited worries about local retail and food outlets in Britain, which are struggling to attract customers much like downtowns in the United States.

"I'm devastated that our much-loved UK restaurants have gone into administration," Oliver wrote on Twitter. "I am deeply saddened by this outcome and would like to thank all of the staff and our suppliers who have put their hearts and souls into this business over the years."

KPMG will oversee the process that affects some 25 restaurants, including the Jamie's Italian chain, the more upmarket Fifteen, and steak house Barbecoa. Overseas branches of Jamie's Italian are not affected, nor is Fifteen Cornwall, which operates as a franchise.

Oliver said Jamie's Italian was launched in 2008 "with the intention of positively disrupting mid-market dining" with higher quality ingredients, animal welfare standards, better service and good value.

But the launch came just as local businesses throughout the U.K. were squeezed by the onset of the 2008 financial crisis. Rising food prices, increasing rents and competition took a toll.

The company had been in trouble for at least two years, despite Oliver's global fame on the back of his cookbooks and television shows. Last year, it shuttered 12 of its 37 sites in Britain, while five branches of the Australian arm of Jamie's Italian were sold off and another put into administration.

He has personally pumped 13 million pounds into his Italian chain, but it was not enough.

"I appreciate how difficult this is for everyone affected," he said.