* Atos needs to raise 600 million euros via debt and equity

* Plans to raise another 600 million via credit lines, guarantees

* Group to reach refinancing agreement by June

* Sees revenue of 9.9 bln eur, operating margin of 4.3% for 2024

* Shares down 14% at 1045 GMT

(Recasts with share reaction, adds CEO comments in paragraphs 5 and 6, financial targets in paragraph 11)

April 9 (Reuters) - Atos shares fell 14% on Tuesday as the French IT consulting firm said its refinancing plan, which includes raising 1.2 billion euros ($1.3 billion) via equity and new loans, would mean significant dilution for existing shareholders.

The technology giant, which manages data and cybersecurity for France's nuclear industry and the upcoming Olympic Games, said in March it was trying to find common ground with creditors over the whole of its debt, which stood at 4.65 billion euros at the end of last year.

Atos said it needs to raise 600 million euros to carry its business through 2024 and 2025 via debt and equity from investors, who can submit financing proposals by April 26.

It also plans to raise 300 million euros in new revolving credit lines and 300 million euros in new bank guarantees.

CEO Paul Saleh told journalists in a call that Atos had agreed with creditors on interim financing of 400 million euros to sustain it until a long-term plan is agreed.

That should allow them to reach a refinancing agreement by June, which would lead to a "significant dilution" for shareholders, Saleh said.

Debt maturities, including 3.65 billion euros due by the end of 2025, would be extended by five years under the planned agreement.

France has pledged to grant another 50 million euro loan to Atos, the Ministry of Economy and Finance said. That will give the state a stronger say over strategic activities at the firm that specializes in spy-to-AI assets deemed strategic by the government.

David Layani, Atos board member and CEO of its top investor Onepoint, at the weekend announced plans to lead a consortium to anchor a possible restructuring plan.

Saleh said Atos would take Layani's plan into account like all others, but that there was no favored proposal at the moment.

Atos, which had delayed giving financial targets for 2024, on Tuesday forecast revenue of 9.9 billion euros and an operating margin of 4.3% for this year. It aims to grow revenue to 11.4 billion by 2027.

($1 = 0.9204 euros) (Reporting by Augustin Turpin and Dimitri Rhodes in Gdansk; Editing by Milla Nissi and Jan Harvey)