Comet said it was "urgently working" on plans to secure the company's future and it is expected that administrators will seek a buyer for the business.
Customers with outstanding orders and those with gift cards and vouchers are being told it is "business as usual until further notice" and that the group intends to fulfil deliveries of products that have been paid for.
Comet's customer care team is handling any customer inquiries on 0844 8009595.
The administration raises the prospect of a pre-Christmas rush for discounted stock, with the administrator expected to wind down supplies and raise cash for creditors.
News of the planned administration follows just months after Comet was taken over by investment firm OpCapita, which bought the chain for a nominal £2 in February.
It is thought OpCapita and recently-appointed chairman John Clare - the former boss of rival Dixons - had been unable to secure the trade credit insurance needed to safeguard suppliers.
Shares of Comet's rivals rose on news of the planned administration, with PC World and Currys parent Dixons Retail leaping by 15%.
Comet's collapse is one of the biggest since the demise of Woolworths in 2008 and comes a month after the failure of JJB Sports. Other recent casualties have included Clinton Cards, Blacks Leisure, Game and Peacocks.
The high street electricals market in the UK has come under huge pressure as cash-strapped shoppers put off purchases of big-ticket items such as TVs and large appliances and online rivals take a bigger slice of the sector.
America's Best Buy recently pulled the plug on 11 giant electrical stores after failing to make inroads into the UK market.
Comet was founded in 1933 by George Hollingbery in Hull as Comet Battery Stores Limited - a two-man business charging batteries and accumulators for customer's wireless sets.
The company moved into the radio rental business and by 1939 had 2,500 accounts.
The first Comet superstore opened in Hull in 1968 and the company was listed two years later, before being acquired by Kingfisher for £129 million in 1984.
Comet then acquired Norweb Retail and increased its store portfolio to more than 250 nationwide in 1996.
It demerged from Kingfisher in 2003, with Comet and its sister electrical companies throughout Europe forming a new group known as Kesa Electricals, which recently changed its name to Darty.
The bleak news about Comet is just the latest in a series of chilling failings to come out of Britain's retail sector this year.
More than a dozen seemingly perpetual names on the high street have become casualties since the credit crunch took hold.
In January, Peacocks, which had 563 stores and 48 concessions, and parent company the Peacock Group, collapsed under a debt mountain in the biggest retail failure since Woolworths, placing 7,500 jobs in jeopardy.
The children's clothing chain Pumpkin Patch went into administration with 400 jobs put at risk - 60 employees had already been made redundant and five of Pumpkin Patch's 36 UK stores closed, but administrator Deloitte said it intended to continue trading until "strategic options" had been explored.
The month got worse with gift shop Past Times appointing administrators from KPMG to try to sell the business as a going concern. The retailer had already closed 46 stores, resulting in 507 redundancies.
Lingerie chain La Senza collapsed into administration in January too, triggering 1,300 redundancies and the closure of more than 100 outlets.
It was a terrible start to the year with Barratts also calling in administrators, who said a deal had been agreed to save most of its shoe chain but at the cost of some 680 jobs.
In March, administrators said almost half the stores run by collapsed retailer Game would close within a week, triggering 2,104 job losses.
Aquascutum, the 160-year-old high-end clothing company, fell into administration in April but the brand was kept alive in May after administrators sold the historic business and saved 100 jobs.
April also saw nine Allied Carpets stores saved - the retailer once boasted more than 200 shops and 1,000 staff, but went bust for the third time in three years.
A month later administrators Zolfo Cooper announced the UK's biggest specialist cards retailer, Clinton Cards, and fallen into administration with 397 of its stores sold to Ohio-based American Greetings.
In June administrators Duff and Phelps were called in by department store Allders, which was established in 1862.
In July around 500 jobs were under threat after discount retailer Ethel Austin went into administration for the fourth time in as many years.
And health food company Julian Graves called in administrators, putting a question mark over more than 700 jobs.
At the start of this month around 2,200 staff at JJB Sports were made redundant after administrators closed 133 stores and agreed to sell 20 remaining outlets to Mike Ashley's Sports Direct International.