Adds source comments in headline and paragraph 1

March 4 (Reuters) - Barclays BARC.L is owed 495 million pounds ($662 million) from its exposure to collapsed mortgage-finance firm Market Financial Solutions (MFS), a source familiar with the matter said on Wednesday.

• The amount, reported earlier by Bloomberg News, is lower than the 600 million pound exposure initially described by the judge overseeing the collapse of MFS, Bloomberg said.

• MFS was placed into administration following allegations of financial irregularities and mismanagement prompting concerns over banks and private credit funds' exposure to the UK-based lender.

• The collapse of the little-known UK mortgage provider has hit bank shares, amid wider concerns about credit contagion in private lending.

• London-based MFS specialised in complex property-backed loans. It had applied for administration, a form of UK insolvency protection, after it ran into difficulties.

($1 = 0.7468 pounds)

($1 = 0.7482 pounds)