看到《元照英美法词典》中有以下法律术语：

moneylender's circulars  放债人通告或通函

offering circular 发行证券通告

在美国，发行证券通告应在证券交易委员会〔S.E.C.〕登记，并随其证券发行而分发。其内容应与招股说明书〔prospectus〕内容类似，提供私募证券发行〔private securities offering〕的相关信息，并受证券交易委员会规则调整。

及

This circular is to provide the shareholders with (i) further information on the Share Subdivision and the Board Lot Change and the re-election of directors of the Company; (ii) the explanatory statement as required under the Rules Governing the Listing of Securities on The Stock Exchange of Hong Kong Limited (the ‘‘Listing Rules’’); and (iii) further information of the final dividend to be declared by the Company and all other information reasonably necessary to enable them to make an informed decision on whether to vote for or against the resolutions as mentioned herein and which, inter alia, will be dealt with at the annual general meeting of the Company to be held at Queensway and Victoria Room, Level 3, J.W. Marriott Hotel, Queensway, Hong Kong on Monday, 23 May 2011 at 2 : 00 p.m. (the ‘‘Annual General Meeting’’).

本通函旨在向股东提供(i)股份拆细及更改每手买卖单位以及重选本公司董事的进一步资料；(ii)香港联合交易所有限公司证券上市规则（「上市规则」）规定的说明函件；及(iii)有关本公司将予宣派的末期股息的进一步资料，以及所有其他合理所需的资料，以便彼等就投票赞成或反对本通函所述的决议案作出知情决定，而（其中包括）有关决议案将提呈于二零一一年五月二十三日（星期一）下午二时正假座香港金钟道万豪酒店三楼Queensway及Victoria宴会厅举行的本公司股东周年大会（「股东周年大会」）处理。

If you have sold or transferred all your shares in USI Holdings Limited, you should at once hand this circular and the enclosed proxy form to the purchaser or transferee, or to the bank, stockbroker or other agent through whom the sale or transfer was effected for transmission to the purchaser or the transferee.

阁下如已售出或转让名下全部富联国际集团有限公司之股份，应立即将本通函连同随附之代 表委任表格送交买主或受让人，或经手买卖或转让之银行、股票经纪或其他代理，以便转交买主或受让人。

个人感觉，翻译为“通告”或“通函”比较好。