By Diana Mandia

(Reuters) - Struggling French IT consulting firm Atos on Thursday said a review of its 2024-2027 business plan would lead to an increased need for cash and potentially additional debt reduction, forcing it to update the parameters of its refinancing plan in the coming days.

Atos also said it would extend the deadline for refinancing proposals from existing stakeholders and third-party investors from April 26 to May 3.

The technology giant, which manages data and cybersecurity for France's nuclear industry and the upcoming Olympic Games, is in the midst of a refinancing, which includes raising 1.2 billion euros ($1.29 billion) via equity and new loans and will result in significant dilution for existing shareholders.

"We will review those proposals with our financial creditors and agree on an appropriate path forward. Our goal remains to agree on a refinancing solution by this coming July," Chief Executive Officer Paul Saleh said in a statement.

Atos said earlier this month it needed to raise 600 million euros to carry its business through 2024 and 2025 via debt and equity from investors, and that it also planned to raise 300 million euros in new revolving credit lines and 300 million euros in new bank guarantees.

The review of the group's 2024-2027 business plan is based on current market conditions and business performance for the first quarter of the year, Atos said.

Atos reiterated its intention to reach an agreement on the company's new capital structure by July.

The company, whose net debt stood at 3.9 billion euros at the end of March, has seen its shares plummet over the past two years after profit warnings, a revolving-door of CEOs and the collapse of potential asset sales, notably its BDS cybersecurity unit and its legacy operation Tech Foundations.

Atos on Thursday also announced sales for the first quarter of 2.48 billion euros, down 2.6% year-on-year, while order entries reached of 1.6 billion euros for a book-to-bill of 64%, compared with 73% in the prior year, reflecting delays in contract awards as clients await the final resolution of the group's refinancing plan.

($1 = 0.9335 euros)

(Reporting by Diana Mandiá; Editing by Mrigank Dhaniwala and Stephen Coates)

Atos says it will need more cash than expected