(Adds background on bid for Adshel, company comment from...

(Adds background on bid for Adshel, company comment from statement)

June 21 (Reuters) - Australia's APN Outdoor Group Ltd (APO) said on Thursday it was assessing a A$1.09 billion ($803 million) takeover offer by French advertising company JCDecaux JCDX.PA , and advised shareholders to take no action at present.

The JCDecaux offer, which is for A$6.52 per APN share, an 11.5 percent premium to APN's last closing price, was submitted by the French company on Wednesday.

"APO shareholders do not need to take any action in relation to the JCD Proposal at this stage," APN Outdoor said in a statement.

The offer comes after APN last month submitted a bid for HT&E's (HT1) outdoor advertising unit, Adshel, for an enterprise value of A$500 million.

APN said the proposal from JCDecaux was subject to a significant number of pre-conditions, including that it does not proceed with the Adshel acquisition.

APN said it was advancing its due diligence for the Adshel buy with a view to agreeing a transaction with Adshel's parent HT&E.

"APO believes that the Adshel proposal is an attractive opportunity for the company and its shareholders," it added, although it cautioned there was no certainty a deal would proceed.

APN's bid had trumped oOh!media's (OML) sweetened A$470 million offer for Adshel. oOh!media then declined to sweeten the deal further.

Last year, Australia's antitrust regulator had blocked a merger between APN and oOh!, citing "substantial lessening of competition". ($1 = 1.3574 Australian dollars)