Exhibit 5.1
                                                                  ------------


                                                              Effective Date:
                                                           9th February, 1999




ACE Limited
The ACE Building
30 Woodbourne Avenue
Hamilton HM 08
Bermuda


Dear Sirs,


Re:   ACE Limited (the "Company") - Form S-8 Registration Statement
      1995 Long-Term Incentive Plan ("the Plan")
      ------------------------------------------

You have asked us to render this opinion in our capacity as your counsel as
to Cayman Islands law in connection with the registration pursuant to a
Registration Statement on Form S-8 (the "Registration Statement") under the
Securities Act of 1933, as Amended (the "Act") of a further
2,564,058 of the Company's Ordinary Shares, par value
US$0.041666667 per share (the "Ordinary Shares") to be issued pursuant to
the Plan approved by Board Resolution on 28th July 1995 and by a resolution
of shareholders at the Annual General Meeting of the Company held on 9th
February 1996.

We have reviewed the Company's Memorandum and Articles of Association (as
amended). We have relied in giving this opinion on certifications from the
Company's Officers.

We assume that all subscription monies due in respect of shares issued by
the Company have been or will be duly received by the Company. We further
assume that all Ordinary Shares to be newly issued in accordance with the
Plan have been reserved for issuance and that there are no intervening
changes in the Plan, the Company's Memorandum and Articles of Association,
the laws of the Cayman Islands or any other relevant matter.

On the basis of the foregoing, we would advise as follows:-






1.    The Company's authorised capital includes 300,000,000 Ordinary Shares
      of US$0.041666667 each, and 10,000,000 "Other Shares" of US$1.00
      each.

2.    The Company has sufficient authorised share capital to issue the
      Ordinary Shares and the issue thereof is within the power
      of the Company's Board of Directors. The Ordinary Shares to be issued
      in accordance with the Plan have been duly authorised and when issued
      and registered in the Company's Share Register in accordance with the
      provisions of the Plan will be legally and validly issued.

3.    On the basis that the contractual subscription price (being not less
      than the par value) of the Ordinary Shares is fully paid in cash or
      other consideration approved by the Board of Directors or a duly
      established Committee thereof, such Ordinary Shares issued or to be
      issued may properly be credited as fully paid under Cayman Islands
      law.

4.    Fully paid shares are not subject to further calls or assessments by the
      Company.

5.    The Company has been incorporated as an exempted company under the
      Companies Law of the Cayman Islands and the liability of its
      shareholders is limited to the amount, if any, unpaid on their shares
      (see Clause 5 of the Memorandum of Association). On the basis that
      all such shares are fully paid, there is no rule of Cayman Islands
      law that would impose any further liability on person holding shares
      in the Company, merely by reason of such shareholding.

We hereby consent to the filing of this opinion as an exhibit to the
Registration Statement.


                                               Yours faithfully,



                                               Maples and Calder



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