Barclays continues to keep investors guessing as to whether it will make a capital call despite yesterday writing down £1.7bn from the value of assets linked to the credit crunch.

The bank irritated some analysts with a lack of detail about the exact nature of the writedowns, with the bank maintaining that cuts varied between assets depending on the solidity of the underlying investments.

But overall the bank wrote off more than £1.7bn against the assets, which was partially offset by gains from the widening of credit spreads on debt held by the bank. Some £500m of these gains reversed in April, the bank added.

Barclays acknowledged yesterday that profits in the first quarter fell short of last year's, although it did not quantify the drop. Analysts' predictions for full-year profits are now between £6.3bn and £6.4bn, a figure the company said yesterday it was comfortable with but which is 10% down on the record £7bn it booked in 2007. Among the other disclosures made by the bank yesterday was that its exposure to monolines, which insure mortgage-related securities from default, had soared as the value of the underlying assets fell.

The company is now exposed by around £2.8bn compared to £1.3bn at the end of 2007.

But it is Barclays' capital position that is attracting the greatest interest. The bank expects its core tier one capital ratio - a key measure of its financial cushion - to be slightly lower at the end of June than the 5.1% it reported at the end of 2007.

Finance director Chris Lucas maintained that the company was still targeting a ratio of some 5.25%, but said the company was prepared to run above or below this level, "depending on circumstances".

This is at variance with many of its competitors. HBOS and Royal Bank of Scotland have already announced capital raising to bring their core capital ratios above 6%.

Analysts at Lehman Brothers calculate that achieving a 6% tier one ratio would require the bank to issue shares worth £5bn, plus more for additional writedowns.

Lucas was giving no hints as to the bank's preferred strategy, even though some observers are tipping it to ask for more money from China Development Bank or Singapore's Temasek Holdings, which picked up 3% and 2.1% stakes in the company last year.

Indications from the bank were that its investment banking arm Barclays Capital had barely broken even in the first four months of the year.

Analysts still think the division could make upwards of £1bn this year if there are no more writedowns, but this compares to almost £2.4bn in 2007.

The bank also surprised observers by indicating that it is prospering in the current mortgage market. The bank said volumes are "significantly higher" than in 2007. Its Woolwich mortgage arm had been struggling to maintain its position in the market until recently.

The bank added that within its UK retail operation impairment charges, from people defaulting on their loans, increased slightly but that mortgage impairment remained low.

But it added that profit before tax in the division fell - due, it said, to previous figures being flattered by proceeds from selling surplus branch buildings.

Richard Hunter, of stockbroker Hargreaves Lansdown, said: "With this uncertainty prevailing and a generally cautious view pervading the UK banking sector at present, the general market view still tends towards a hold for Barclays."