Marius Niculae was at Sporting Lisbon for four seasons

The 26-year-old, released by German club Mainz following their relegation, is expected to sign on Wednesday after he obtains a work permit.

Caley Thistle head coach Charlie Christie told his club website: "This is a big signing for us, to bring in someone with 26 international caps.

"Marius played in the Bundesliga last season, so he clearly has the quality."

Interview: Inverness striker Marius Niculae

Signing Niculae, who has scored six times for his country, will break Caley Thistle's wage structure.

But club chairman Alan Savage has sponsored the player through his company, The Orion Group.

We had talks which saw Marius agree to significantly reduce his initial financial requirements Inverness director of football Graeme Bennett

And Inverness say that the player also significantly reduced his initial wage demands.

Savage said: "My company does business in Romania and Nikulae was recommended.

"When Charlie was shown the DVD of the player in action, he immediately said he's love to get him.

"It is a rare opportunity to land an international player who was a free agent, thus involving no transfer fee, and the club directors were very keen to help the manager strengthen for the new SPL campaign."

Inverness had hoped he would sign in time for the club's training trip to Italy at the start of July.

But the Romanian, who can also operate in midfield, returned home to consider his options.

There was competition for his signature from clubs in Switzerland and Turkey, but he will now return to training with Inverness on Wednesday.

Director of football Graeme Bennett added: "We are delighted to be able, subject to the work permit, to recruit someone of Marius's calibre within our existing football budget.

"The player returned to Inverness on Monday evening and we had talks which saw Marius agree to significantly reduce his initial financial requirements."

Niculae moved to Sporting Lisbon from Dinamo Bucharest in 2001 and spent four seasons in Portugal before his switch to Germany.

MY SPORT: DEBATE Give your reaction to Caley Thistle's latest signing

Meanwhile, Austrians Dominique Taboga and Benedict Bauer have also started week-long trials at the Caledonian Stadium.

Taboga, a 24-year-old centre-back, is on the books of second-tier side SV Kapfenberg.

Nineteen-year-old striker Bauer recently signed a contract extension with Third Division club Admira Wacker.

Christie is also considering flying over an unidentified French defender in the next couple of days, with discussions ongoing.